9 Developing an Information System

8/11/2019 9 Developing an Information System

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9Developing an

information system

Build a system that even a fool can use, and only a fool will want to use it.Shaw's Principle

OverviewWe are now ready to put together everything we have learnt so far. Starting from a taskdescription we will develop a working information system following the DDE cycle.

To do this we will look at:

what can be achieved data flow diagrams the information system development process

internet abuses.

IS reviewSo far we have found that in general the following operations are associated with an

information system:

Design

establish the facts and relationships

determine constraints or restrictions decide table structure identify field properties.

Manipulate data

retrieval (queries, sorting, functions) insertion and deletion update or modify execute procedures.

Kevin Savage 2011 Single user licence issued to Mitchell Ingall


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Leading Technology 304

Presentation

display (soft and hard copy) report (summary).

Security

ensure confidentiality of sensitive data restrict access to only relevant data ensure integrity from accidental or deliberate error.

In the computer industry such an information system is usually developed by a team. This teammight consist of a project manager, a systems analyst or analysts, programmers, and so on.

Through the project manager these will liaise with the owner of the system, the UoD expert,and the end users. The aim is to design a system that works for them. In addition thedevelopment process would also involve the training of users, the preparation of work

procedures, maintenance of the system when in place, and reviews of its relative value.

If we try to do all of this ourselves we will run into great difficulty because we are restricted inwhat we can do in a classroom. When it comes to modelling real-world situations we do nothave the time, expertise, or access to data that a real systems designer would have. We arelimited in the complexity of the systems we can develop and in the sophistication of what wecan achieve.

With this in mind we will cover as much of the process as we can and, in doing so, get a feelfor how an information system is developed in the industry.

Before we begin this process however we will first look at data flow diagrams as an alternativeway of describing the connections between the parts of an information system.

Data flow diagramsA data flow diagram (DFD), as the name suggests, shows how data flows through an

information system. It is different from a conceptual schema diagram in that it concentrates on

how the data is processed (changed) rather than the objects and relations in the system. Bylooking at the flow of data we not only see the information system from a different perspective,

it will also give us a good idea of the inputs and outputs, to and from the system.

A DFD shows how data enters and leaves a system, how it moves from one process to another,

and where it is stored. Over the page is a DFD for a student enrolling at a school:

In a DFD sources or destinations of data, such as students or teachers, are represented as

rectangles.

In this example the student to be enrolled provides details such as name, age, gender, etc. This

data must be checked to see if it is complete, if it contains any obvious errors, or if there are

any problems. Arrows represent this flow of information, from and to the student, while a

rounded rectangle shows the process involved (check details).

Aprocessis where data is taken as input, something is done to it, and then an output is made.

Each process must therefore have at least one input and one output arrow.

Once checked the data can then be input into the student database. The student must also be

added to a year group, and added to class lists. As part of this last process the student will get to

choose which subjects he or she would like to do. Again arrows show flow of data, rounded Kevin Savage 2011 Single user licence issued to Mitchell Ingall


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Developing an information system 305

rectangles show processes, while an open ended rectangle represents the data store (student

database).

School enrolment DFD

Once all the data has been added to the student database it can then be used to generate

information such as class lists and timetables. These are provided to students and teachers.

If you wish to add more detail to a DFD the processes and data stores can have identifyinginformation added.

The process can be numbered to indicate its place in a sequence, with sub-numbering (3.1, 3.2,

etc.) if required. The person or device making the change to the data is recorded at the bottom.

If there are a number of data stores they can also be identified by a code.

The best way to develop a DFD for a given scenario is to use either a whiteboard or a large

sheet of paper. The situation should be talked through, preferably by more than one person, and

the inputs, outputs, processes and data stores identified. Changes should be made as necessary

until a representative diagram of the flow of data is achieved.

Student database

Student checkdetailscorrect

inputdata

add toclasslists

add toyear

group

student details

omissions/errors

checked forms

student details

year

subjectssubject choices

timetable

Teachers

class lists

3.0

add toyear group

Yrcoordinator

Student databaseD1

Room scheduleD2



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Activ ity 9.1 Flow of data

1. Write a paragraph describing the flow of data through the school enrolment scenariodescribed above. Assume a typical student and describe the data collected, where it goes,

and what processing it undergoes.

2. Identify the sorts of data that flows between student and teacher, and teacher and parent.

Draw this on a diagram like the following:

3. Explain what each of the following is in a DFD and draw the symbol used to represent it.

a An external source or destination of data.

b A flow of data.

c A process.

d A data store.4. The diagram below shows the flow of data for theRepairsdatabase used earlier.

Owners of computer and other equipment to be repaired will leave the device with the

receptionist who will tell them when it is ready to be collected. The receptionist will

record the details on the computer. From the computer the foreman will allocate jobs to be

performed by the technicians and himself.

Represent the information from the diagram as a DFD.

technician

owner receptionist

foreman

name, device

ready, cost

job# readycost

namedevice

job#tech#date

rate, priority,tech details

job#, device, priority

job#, ready, timecurrent jobsComputer

parentstudent teacher



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5. Cyrus Habberschold owns an art gallery and has asked you to develop an information

system to keep a record of all his artworks from acquisition to sale. Cyrus does not own

the artworks, his gallery is merely the agent for their sale.Cyrus would like to keep a record of the artwork and the details of the artwork such as

title, artist, type, medium, assessed value, etc. He wants to record the details of ownership

of each artwork. An owner can own more than one artwork.

Cyril would like to use the system to prepare a catalogue which is an alphabetical list of all

the artworks available for sale with artist and assessed value. Records of sales are also to

be kept including purchaser details. This will form the basis of a mailing list for future

promotions.

Each month Cyrus prepares a statement to each owner who had artworks in the gallerydetailing the outcome of any sales.

Represent the above information as a DFD.

6. Fleet Hire Motors provide chauffeur-driven prestige vehicles and would like a database of

all vehicles that are currently part of their fleet. Apart from the usual details of make,

model, hire cost etc., date of purchase, purchase cost, and vendor are to be recorded.

Vendors can be the providers of more than one vehicle. Chauffeur (driver) details are to be

recorded with both home and mobile phone numbers, and hourly work rate.For each hire, vehicle and chauffeur are to be recorded, as well as number of hours hired,

and distance travelled, plus customer details. Fuel costs for each vehicle are also recorded

as are service costs and details. Accidents and the appropriate damage details should also

be stored.

Represent the above information as a DFD.

7. a Prepare a CS diagram for Q5 above.

b Compare the CSD representation to the DFD. What sorts of information about thesystem is provided by each diagram?

c Repeat for the scenario in Q6.

Information system developmentIt is now time to create an information system from scratch.

The information system development process is similar to the software development cycle.

Overall we follow the same design-develop-evaluate (DDE) cycle, but there are differences in

sub-steps as detailed below.

Identify

general problem description a simple statement of the overall task rationale for development the reason this system is being developed assumptions and boundaries the limits we place on the task to make it manageable.

Conceptualise

aims and objectives what we intend to achieve Kevin Savage 2011 Single user licence issued to Mitchell Ingall


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data flow diagram a schema identifying how data travels through the system input and output requirements what data is to go into, and what information we

want to be reported by the system.

The Information System Development Process

Formalise

normalised relations data organised into relational tables data dictionary a list of the fields that make up the system with their associated

properties.

device specification the hardware and software needed to implement the system screen and report layout a sketch plan for input and output screens or hard copy

menu design a tree diagram showing menu options interactive devices an outline of how the user will work with the system, including

how user assistance will be given

Implement

database and tables input forms queries

output reports menu.

Test

ensure the system works in all situations with all data.

Evaluate

function compare the operation of the system with the original specifications todetermine if the stated objectives have been met



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implementation comment on the performance, reliability and ease of use of thesystem; suggest possible improvements that could be made

process discuss the effectiveness and efficiency of the development procedure.

Document

specification documentation written record of the first three steps hard copy representative sample of activities in the implementation phase evaluation detail of ongoing and formal evaluation log record of activities that describe the development process help system user manual or on-line assistance to users.

We will now work through each of these steps based on the following scenario.

ScenarioThe owner of Porkies Dial-a-Rib has decided to set up a computerised system to help with his smallbusiness. The current system is paper based, and is not keeping up with the growth of theenterprise.

Porkies works out of a kitchen in a shop. All orders are taken by phone and delivered by drivers.There are no walk in or pick-up orders taken.

Over the page is a copy of Porkies menu:

IdentifyTo gain a clear idea of this task it is important to distinguish exactly what it involves. To do this

we will prepare a general problem description, a rationale for development, and we will

identify the assumptions and boundaries of the scenario.

General problem descriptionA general problem description is a simple re-statement of the overall task. To prepare this

description read the information provided carefully and pinpoint all relevant features. Ifnecessary you may expand on the information provided to give a clearer picture of the scenario

as you see it. When you are sure you understand what has to be done rewrite the task in your

own words.

In real life you would interview the system owner, UoD expert, and end users, and would be

able to provide both background and specific detail. In a classroom situation some

inventiveness may be necessary to provide such background and detail.

General problem description: Porkies Dial-A-Ribhas been operating for two years now. It grew out

of a small cafe operation where the owner, John Porky Thompson, offered ribs as part of the menu.These proved so popular that he specialised in just ribs. Soon he decided to employ a driver andoffer home delivery. In time Porky Thompson closed the cafe operation and only accepted ordersgiven over the phone. At present the business has grown to the extent that on most nights threedrivers are needed to make deliveries.

Originally orders were taken by Porky and written on scraps of paper while he made up the ordershimself. He has now found it necessary to employ a phone operator and a kitchen hand to help himkeep up. The system of writing orders on scraps of paper no longer works; orders have been mixedup and even lost. Porky has decided to computerise the ordering system.



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In the new system customers will ring through their orders for ribs and other items from the menu,such as soft drinks and garlic bread. No products are to be sold other than over the phone. Eachorder is taken by the phone operator who enters customer details and both the code and the quantity

for the particular items required. Orders are not accepted from public telephones. The time of orderis noted.

The total cost of the order is calculated by the computer and the customer is informed. The operatoris also responsible for allocating the order to a particular driver. On a given night there are up tothree drivers, each with their assigned vehicle. The order is displayed on a monitor in the kitchenwhere it is prepared and made ready for the driver. A copy of the order and address is given to thedriver who then collects the order and takes it to the customer.

Porkies Dial a Rib

Fast free delivery - 7 days a week - 5pm till 10pm

MenuRibs Regular Large

BBQ sauce $8.50 $10.50Chilli sauce $8.00 $10.00Smokey Bacon sauce $8.25 $10.25

Side OrderFried Rice $2.95Chips $1.95Garlic Bread $1.60

Drinks Bottle CanCoca Cola $1.10 $1.20Fanta $1.10 $1.20

Sprite $1.10 $1.30Salad Small Large

Coleslaw $1.50 $2.75Green Salad $1.40 $2.50

Phone: 399 111Just phone Porkies and give your name, address, suburb, and phone number to place

your order. Free delivery direct to your door in around 30 minutes.

A welcoming light turned on outside would be appreciated by our driver.

Drivers carry change for $20 only. Limited delivery area.

Minimum order $10. Prices subject to change without notice.

Rationale for developmentA rationale is a reasoned justification for why a particular process is being followed.

In developing an information system in real life it is necessary to identify the reasons behind

the decision to proceed with the system. The justification might include a cost-benefit analysis,

detailed examination of current processes, investigation of alternatives, trade-offs that had to be Kevin Savage 2011 Single user licence issued to Mitchell Ingall


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made, and so on. It would also include an estimate of the cost of development both financially

and in terms of time and effort. The rationale is to provide clear evidence of why there is a need

for this system and how it would add value to the enterprise.For our purposes we will limit our rationale to just identifying the benefits that would result

from implementing such a system. Again some inventiveness may be necessary to provide

sufficient detail.

Rationale for development: ThePorkies Dial-A-Ribinformation system is to be implemented toimprove the efficiency, accuracy and timeliness of the ordering operation and to increase customersatisfaction.

By computerising orders they need only be entered once and can be checked by the system toensure values are within limits. The order can be accurately and quickly transmitted to both thekitchen and the driver. It can also be totalled by the computer and records kept of transactions. Thesaving in time of processing the order and the certainty that the customer will receive prompt andcorrect delivery will improve customer satisfaction and lead to regular clientele and generate newbusiness. In turn this will make the business more profitable and increase the possibilities forexpansion.

Employees will benefit from the ease of use, accuracy and speed of the new system. As theybecome more proficient in using the system, a higher level of staff morale should be developed.

The system will ensure that information is correct, up-to-date and consistent. Data may also beeasily accessed, and additional information will be available so that Porky can make well informed

decisions for the future operation of the business.

Assumptions and boundariesThe assumptions and boundaries (UoD) are the simplifications or limits placed on the system

so that the task is manageable and that it is practical to implement.

UoD: This system will encompass the owner (Porky Thompson, also UoD expert), the customers,phone operator, kitchen staff and drivers. Data from the menu will be stored on computer as well asdetails of orders taken and the customer who orders them. The computer will also record the time oforder, its total cost and the driver assigned.

The system will not be concerned with inventory of stock on hand, wages, profits or otheraccounting. Archival records will not be kept.

Since there is no confidential information in the system it will not need password access, however itwill pay to lock menu items and values to prevent accidental changes.

Assumptions: In developing this system we will make the following assumptions:

there is only one phone operator who is responsible for checking the delivery area andthe minimum cost of the order

drivers are not assigned suburbs and will deliver orders one at a time as they areprepared

a driver is always available

details of previous customers are not kept on computer

items are identified by a code for ease of entering into the computer

each order is identified by an order number

each customer name is unique

all orders are from private addresses though there may be two different orders from oneaddress (e.g. a party)

a customer can make more than one order per night (but on a different order number).



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For simplicity we are excluding such practical considerations as money handling; staff rostering;archival details (stock available, total sales, time worked, etc.) and customer complaint handling.

ConceptualiseOnce we have a clear idea of what we have to do, we can start to look at how we might do it.

This is the conceptualisation phase where we form a clear picture of how the completed system

might look as a final product before we begin.

To do this in real life you would investigate the system in place to determine the users

requirements, but for this task we are limited to the data given in the scenario.

To form the conceptualisation we will develop:

aim and objectives a brief statement of what we expect to achieve by developingthis system and a list of the requirements of what the completed system is to do data flow diagram showing the important parts of the system with arrows to

indicate what data is handled, and who or what it is passed to or comes from

input and output requirements the data to be entered into, and the facts and figuresthat are to be extracted from the system.

Aim and objectives: Our aim is to develop a working information system for Porkies Dial-a-Rib. Thesystem will be user friendly, user proof and well documented, and will run with no errors.

We will develop a menu based information system that will record information about orders andtransactions. The system will accept new input as customer details and orders. It will also enable theoperator to assign drivers. The computer will total bills and keep a record of transactions for oneevening.

Output reports on takings for the evening and the current state of orders will be made available toPorky. There will also be a delivery form prepared for drivers and an on-screen report for the kitchento see orders that have to be made up.

Data flow diagram:

Data flow diagram for Porkies Dial-a Rib



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Input and output requirements: The phone operator will require an input screen to enter customerdetails and the items ordered. It will pay to create a code for menu items to speed up the data entryprocess. On the input form there will be a field for the operator to assign a driver, as well as fields for

time of order and total cost. The owner will initially need to set the menu and cost of items but sincethese are not often changed we will not have a set form for their input.

Drivers will have to indicate when they have returned and are ready to deliver another order, but thiscan be done directly to the phone operator and will not need to be entered into the system.

FormaliseFormalisation is where we start to flesh out the conceptualisation by going into specific detail

of how the system is to be implemented. To achieve this we will develop the following:

normalised relations organise data into relational tables data dictionary a list of the fields that make up the system with their associated

properties

device specification a list of suitable hardware and software that could be used toimplement the system

screen and report layout a sketch plan for input and output screens menu design tree diagram showing menu options interactive devices outline of how the user will work with the system (including

user assistance).

Normalised relationsThis step involves the development of the CS diagramand the ONF tablesby preparing the

following:

entities identify the entities and show links between any that may be related elementary sentences develop a set of elementary sentences to describe the

relationships in this UoD

conceptual schema diagram convert the elementary sentences into a draft diagram refine the diagram simplify the diagram by eliminating surplus entities and by

indicating derived facts

constraintsand assumptions add uniqueness, mandatory and other constraints to thediagram and include any assumptions made

loops establish table loops around relation groups that are many:1 or 1:1, andaround any many:many relations

normalised tables from the loops form named tables and indicate keys and other

relevant information data dictionary from the tables work out the field properties required.

Once this is done we can implement and test the system.

Elementary sentencesTo develop the elementary sentences we will firstly need to identify the entities in the system.

To do this we will need to carefully re-read the task description and also what we have written

in the general problem description, aims and objectives. From that we can then look carefully at

the data flow diagram and input form to identify potential entities. Kevin Savage 2011 Single user licence issued to Mitchell Ingall


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From all of these we might end up with the following list of entities:

customer street suburb phone

order time item item cost quantityorder total cost driver order ready vehicle

On further thought we might realise that we will also need an entity called order. Using an

order number we can identify a specific order to tie together all of the information a customer

provides and to track it through the system. Identifying the order by number rather than by

customer name overcomes problems such as repeats of names or a second order by the same

customer.

We may also realise item will be identified by both an item code and an item description.

If we put all of these entities onto a sheet and draw lines showing entities that might be relatedin any way we may come up with something like the following:

This will help to us develop the elementary facts and from them the elementary sentences:

customer (name) A. Mackie customer (name) A. Mackielives at / is location for abides in / is area foraddress (street) 18 Chinchilla suburb (subname) Harlaxton

customer (name) A. Mackie customer (name) A. Mackieis found on / is number for placed / was placed by

phone (phonenr) 345678 order (order#) 0038order (order#) 0038 order (order#) 0038was placed at / for placement of has total cost of / is total cost fortime (am/pm) 7:30pm money ($) 22.50

order (order#) 0038 driver (driv#) D02is assigned to / delivers is allocated / allocated todriver (driv#) D02 vehicle (veh#) 2

item (itemcode) R-BBQ item (itemcode) R-BBQis code for / has code of is priced at / is price of

item(itemname) reg. ribs-BBQ sauce money ($) 8.50

order (order#) 0038 order(order#) 0038has status / is status for includes / is onready (Y/N) yes item (itemcode) R-BBQ

in number / ofquantity (nr) 2

All elementary sentences are binaries except the final one which can be represented as a nested

ternary.



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Conceptual schemaOur first draft of the conceptual schema diagram based on the elementary sentences will give

us:

Surplus entities and derived factsThe next step is to check for surplus entities and to see if any facts can be derived.

It does not take much to realise that both item cost and total cost are both money and so these

two entities can be joined into one. They will be handled in exactly the same way as each other

by the system.

What about entities like phone number and quantity, or driver number and vehicle number?

Perhaps these could be combined but they are not similar enough, and besides we would get

really confused if driver and vehicle numbers could be mistaken for each other. We will leave

these as separate entities.

The only fact that can be derived is the total cost for an order. This will be the sum of item cost

times quantity for a given order. (While time of order cannot be derived it can be determined by

the system.)

We will make these changes to our CS diagram (as shown over the page).



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ConstraintsWe will now redraw the CS diagram and add uniqueness, mandatory, entity and frequency

constraints:

( item cost x quantity )Normalisation



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Placing loops around the relations in the above diagram will result in the following normalised

tables:

Customer: ( name, street, suburb, phone )Order: ( order#, name, driver, time, ready, totalcost )

Menu: ( itemcode, itemname, itemcost )

Quantity: ( order#, itemcode, quantity )

Driver: ( driver, vehicle )

Data dictionary:

Field name Data type Size Format Required Notes

name text 25 Y key for Customer

street text 35 Ysuburb text 25 Y

phone text 8 0000 0000 Y

order# number 5 00000 key for Order

driver text 15 Y key for Driver

time date/time hh:mm Y

ready yes/no 1

totalcost currency $###.## derived at run time

itemcode number 5 0000 key for Menu

itemname text 25 Y description of item

itemcost currency $###.## Y

quantity number 3 ### Y

vehicle text 5 Y

Formalisation (cont)

Now that we know what will be in our system we can complete the formalisation with a devicespecification, screen and report layout, menu design and interactive devices.

Device specification: This system will need a computer for the phone operator (and perhaps theowner) as well as a screen and some input device in the kitchen. A printer will also be required toprepare delivery instructions for the drivers. Software will include Access 2010 and Windows 7.

In the kitchen a monitor to display the current orders will be linked into the system with a mouse orjoystick used to indicate which orders are ready.

Output reports: The system will produce the following output reports:

Report Detail Prepared for

deliveryaccount

driver, order number, customer name, street and number,items and quantity, time of order, amount owing

driver

kitchen order number, items and quantity, time of order cook

current orders order numbers, items and quantity, driver allocated owner

takings total value of evenings orders owner

*



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Screen layout:

Porkies Dial-A-RibOrder number:

Customer name: Contact phone:

Street address: Suburb:

Code Item Quantity Cost

Total:

Time of order: Driver assigned:

Menu design: The application will run through the following menu structure.

Main Menu

Interactive devices: The phone operator and owners interaction with this system will be providedthrough an Access interface. This will be started from a desktop icon. There will be no passwordaccess.

On start up the user will be presented with the main menu. Movement through this system will be bymouse action on standard buttons. Directions and help will be available for all actions.

In the kitchen a list of orders will be displayed this will be an on-screen report. The display will beupdated as each new order is filled. Movement through the orders on the report will be by mouseaction. Kitchen staff can click next to an order when it has been made up.

Exit will be from a main menu selection. The program will automatically save data to disc.

Enterneworder

Orders Owner Exit

Viewcurrentorders

Printorder

Updateorder

Deleteorder

Returnto mainmenu

Returnto mainmenu

Viewtakings



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Activity 9.2 Implement and testWe are now at the stage of working from our design to turning our conceptualisation into a

functioning information system.To do this in turn we will set up each of the following:

database and tables create the database and tables working from the ONF design,and then populate the tables

input forms make the data entry forms queries develop any queries needed output reports create formatted reports

menu structure add the switchboard and macros needed to run the application1. Use the normalised tables above set up the database for Porkies Dial-a-Rib in Access.

Populate the tables with information from the menu (see p318) and with sample customer

orders.

2. Develop the following queries to be used on the input form

a Cost: multiply itemcostfromMenuby quantityfrom Quantity.

b Item name: display itemnamegiven itemcode.

3. Create the data input form as per the design on page 318 and using these two queries.

4. Develop the following queries and use them to create the output reports listed on page 318:

a Deliver: using fields fromDriver, Customer, Quantityand Order(amount owing will

be an expression).

b Kitchen: using fields from Quantityand Order.

c Current: also using fields from Quantityand Order.

d Takings: totalling the cost of all orders and using fields from QuantityandMenu.

5. Add a menu system to run the application.

The application should include on-screen cues for users. Ensure there is a consistent

format in screen presentation and similar actions are carried out in the same way, e.g. to

exit to a previous screen.

6. Test the system to ensure it works effectively in all situations. The system should be tested

both by yourself and at least one other person who is not familiar with it, to ensure it is

easy to use and is user proof. Use a variety of test data to prototype the system effectively.

EvaluateOnce completed the effectiveness of the system must be judged and the system has to be

documented.

Evaluation should reflect on:

function compare the operation of the system with the original specifications todetermine if the stated objectives have been met



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implementation comment on the performance, reliability and ease of use of thesystem; suggest possible improvements that could be made; comments made by an

unfamiliar user would be useful as part of an evaluation process discuss the effectiveness and efficiency and the development procedure

with comments on working in pairs if relevant.

Function: The system as implemented meets the requirements of the initial specification.

The performance of the application is good and provides the business with a quicker moreprofessional service for its customers. The increased efficiency of orders appearing on the kitchenscreen immediately upon entering the computer system and the accurate print out of order andcustomer details for the driver ensures no mix-ups.

With a unique identity number each order has an individual reference that is used by the phone

operator, kitchen and driver and provides a direct link between the physical order and the customersdelivery instructions.

Being menu driven and user friendly the program is easy to use. The menus are explicit in what is tobe done and there is error checking to ensure valid values are input. A user manual is also providedfor reference.

One disadvantage is that the business will now be dependent on the system and major problemsmay occur if the system goes down for any reason.

Implementation: As implemented the system is still not complete and will need to be upgraded toinclude the driver, and kitchen sections.

The system is reliable if users are careful not to enter invalid data or make inadvertent deletions. It isalso easy to use with actions obvious from the directions on buttons. One problem is the need toclose a window to return to the main menu and this might be difficult for novice users.

Improvements that might be included could be:

providing an on-screen menu for the phone operator to refer to when answering calls

archiving customer data for ease of data entry (with a customer number for regulars) and thepotential of a mailing list for advertising of special offers

provision of further reports for the owner (stock, income etc.)

an on-line help facility would assist in learning about the system and would increase theconfidence of the users in that they would know assistance is readily at hand

a better interface, e.g. voice activated in the kitchen where hands might be sticky or greasy

user proofing the system so that users can only enter valid values

prompting the phone operator to confirm the deletion of orders

a security system such as password access to prevent anyone other than the owner fromaltering menu or prices

a back up system to come into play if the main system went down

including a splash screen with business name and logo to welcome the user at the start of theapplication.

Process: In this case the process of implementation has been very smooth and we have achievedwhat we set out to do.

DocumentThe documentation should have been collected throughout the process up to this point to

chronicle the whole process of development of this information system. It is to be collated in

order, be neatly presented, and should consist of: Kevin Savage 2011 Single user licence issued to Mitchell Ingall


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general problem description and rationale for development list of assumptions and boundaries

aims and objectives data flow diagram input requirements and output reports device specification and screen designs menu design and interactive devices to be employed elementary sentences a copy of the conceptual schema diagram and normalised tables data dictionary

printouts of table definitions and contents screen captures to show the main menu and order entry form printouts of reports generated evaluation user manual if included.

For a system as simple as this a user manual might be overkill, but if we did produce one it will

need to inform the user:

what the system does how to start the system basic methods of how to use the system what to do if something goes wrong how to finish.

In addition you might like to include a copy of the menu schema to assist the user.

Such a manual might start like this:

User Manual:

Porkies Dial a Rib

1. About the system

2. Getting started

3. Operating the system

4. Getting help

5. How to finish off.

1. About the System

Porkies Dial-a-Rib information system is designed to increase the efficiency and overallmanagement o f the business of w hich you are a part. This computerised system is fasterand more reliable than a paper based system as a result of better organisation, increasedease of use and greater accuracy wi th orders. The system is easy to use and provides youwith help messages at every stage.

The system collates and sto res orders coming in. Details about customers and orders areentered by the phone operator. The system then assigns an order number and a time oforder, and calculates the total cost of the order. These details are passed onto the kitchen



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and the drivers. The system will di splay information about the menu, orders pendingdelivery and orders to be filled. The system also prepares the delivery slip.

Output reports on The state of current orders and evenings takings are also available.

2. Getting Started

After start ing the computer cl ick on the Porkies icon on the desktop to gain access to themain menu.

The menu offers opt ions and sub-options o f:

Orders place, prin t, delete, update and return to main menu

Owner view current orders, view takings and return to main menu

Exit

Each entry on the menu is activated by pressing the associated button or Alt + the

underlined letter. To exit from a menu item press the Continue button3. Operating the System

3.1 Orders Menu

etc. ...

Possible IS ScenariosThe following scenarios are ideas for suitable information systems.

1. Jacki Jones is in the process of setting up a new taxi company that she will call Kwika

Cabs. She wishes operations to be computer based and has contracted you to develop the

information system.

Jacki intends to offer four categories of cab (ordinary, maxi, courier and limo) each with

its own rate of hire. Cabs also have different rates of hire for day and night (after 6 p.m.).

Each vehicle is to be owned and run by independent operators.

To maximise income taxi owners keep the vehicle on the road as much as possible with

drivers (usually including themselves) operating in shifts. The contact phone number foreach owner and driver must be held on the system.

When a customer phones up, the dispatcher will record the name and pick up point. At

times the dispatcher may request a contact phone (e.g. if he suspects a prank call). The job

is then assigned to the nearest vacant taxi and the driver is informed by radio. The time the

cab is sent is also recorded in case the customer phones back to enquire about delays.

Prepare a system that will assist the dispatcher in assigning cabs to jobs and also record the

operations for a given day (6 a.m. to 6 a.m.). As Jacki intends to charge owners in

proportion to the number and category of jobs they are given, the system must be able togive details of which cabs were in use, when, how and where they were used, and by

which customers.

2. Mike and Jane Edwards have recently taken over a small run-down motel on the New

England highway just south of Toowoomba. They have almost got the motel ready for

service but would like a computer system to record operations and have asked for your

help.



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The motel has fourteen rooms, six single, six double and two family, each with its own

rate. Rooms may be booked in advance, but most are taken on a casual basis when

travellers stop by. Occasionally a group may book in, in which case a discount can be

offered. The name, home address and (unless paying by cash) the credit card of the

customer who books the room is recorded. A record must also be kept of the value of

phone calls, room service and mini-bar sales for each room.

Mike and Jane would like a system that will show which rooms are available for a given

date, and a record of customers and takings.

3. The Bunyip Art Society presents an annual exhibition. The Art Show is now established as

an important event in the societys calendar featuring work from artists from around

Australia. Invitations are extended to prominent artists, and artists who have exhibited theprevious year, to show their work for sale. The art may be paintings, sculpture, jewellery

or other media.

A catalogue is prepared for the Art Show detailing the works of art and their location in

the gallery. A receipt is issued to the customer whenever a sale is made and the society

receives a commission as agent.

At the end of the show, an account is sent to all artists detailing sales, commissions

deducted and totals forwarded. A summary report is then prepared for the Art Show

Committee.

The societys committee is not satisfied with their existing method of recording data and

have engaged you to set up a computerised information system to record data.

Hint: you might like to refer to your answer to the art gallery DFD in Activity 9.1.

SEI 9 Internet abuses

The most prevalent information system currently is the internet. Unfortunately there are many

who will abuse and twist it to their own ends. Information a user provides for one purpose canbe used for other unrelated, and often intrusive, purposes. In this section we will investigate

some of the forms these abuses can take.

SpamSpamis electronic junk mail. Like personalised marketing the person promoting something for

sale sends information to consumers, but in this case it is sent by email. While ordinary junk

mail or personalised mail will cost upwards of fifty cents each to

deliver, thousands of spam mailings can be posted for a few cents.

The name spam derives from a Monty Python sketch in which

four Vikings loudly sing the praises of spam (a meat substitute)

and drown out the voices of the other customers. In the same way

email spam floods mailing lists and threatens to drown out normal

communication. In addition to email there is spam on text

messaging, fax machines, IM, blogs, social network sites, and so

on.



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Spam mailing lists are often compiled by unethical (or even illegal) means. One way is to use a

program called a spambotthat works its way through web sites, blogs, social sites and

newsgroups, harvesting addresses as it goes. Another is to collect and then sell lists of

addresses of people who provide information via on-line forms. There are resources available

to spammers that give details of over 50 million current email addresses.

The extent of spam is amazing. Some estimates suggest that there are tens of billionsof

unwanted emails a year, and the use of spam in newsgroups could be well over 50% of traffic.

The arrival of spam on a home computer is annoying, but the sheer volume of traffic it

generates on the internet significantly slows down operations.

It is possible to install software on your computer to filter out spam but ironically some

companies even use spam to advertise anti-spam software! The net community is doing what itcan to fight back by blacklisting spammers and notifying ISPs of originating addresses. There

are legal steps being proposed, but the international nature of the internet makes this difficult.

There are already laws in many countries that attempt to regulate spam.

Some civil liberties groups are concerned about so called stealth blocking. In this ISPs use

aggressive spam blocking without their customers knowledge. The concern is that ISPs

seeking to reduce spam-related costs may also block non-spam e-mail.

This anti-spam message is itself spam

Spoofing and phishingSpoofing is where a person is able to masquerade as another. A typical example is where

unscrupulous persons pretend to be younger, or a different gender, in chat rooms or on

channels. This is simple to do because those concerned are not face to face, and identities can

be anonymised.



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Spoofing can also apply to programs or files. In some cases music copyright holders have

flooded file sharing networks with unlistenable versions of popular tracks to discourage

downloading.

Web page spoofing is where the legitimate page is replaced by another. An early case where

this occurred was when the official White House web site was spoofed. Hackers had found the

site was not protected and changed data on the site. Visitors were surprised to see some very

uncomplimentary comments about the then US president Clinton. Another way of spoofing a

web site is topharm(intercept) the original web address and redirect the user to another site

that superficially looks like the original.

Spoofing can also be used as part ofphishingwere an attempt is made to acquire information

such as passwords or credit card details. The person behind the attempt fishes for theinformation (the ph comes from the older practice ofphone phreaking).

Phishing is a form of social engineering, and is carried out by masquerading as a trustworthy

person or business in an email, web site or instant message. In a typical phishing attempt the

target will receive a message saying that they have to verify their account, by following a

link to what appears to be an authentic website. In reality the link is forged, although this is

very difficult to spot as everything from the web address to the screen appearance is the same

as the original.

A phishing attempt to obtain an eBay password

The damage caused by phishing ranges from loss of access to email, to financial loss if bank

account passwords are stolen.

Phishing can also be used in identity theft. Unsuspecting people will often divulge personal

information including credit card, passport and tax file numbers. In this format phishing is also

known as carding(from credit card). Once information is acquired, the carders may use a

persons details to prevent them from accessing their own accounts, ruin their credit rating, or

even create fake accounts in the targets name.



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One strategy for combating phishing is to train users how to deal with phishing attempts. There

are also anti-phishing programs available which work by identifying typical phrasing used in

emails or on web pages. Spam filters also limit the number of phishing emails that will

penetrate a system. Some banks now also use challenge questions in addition to password

access. The answers to the challenge questions are known only to the legitimate user and the

bank, and therefore not the phisher.

SpywareAs mentioned in unit 5 spyware is the name given to programs that are loaded onto a computer

without the users informed consent. Once installed these programs can monitor the users

actions or collect information about the user for commercial purposes. The computer has been

subverted for the benefit of someone else.The most visible behaviour of spyware is usually to promote contact with selected sites by

displaying pop-up ads. These are advertisements that appear on the computer at regular

intervals, or alternatively, whenever the user opens a new browser window. The spyware

monitors the users web browsing interests and habits by recording sites visited, and attempts to

develop a profile of the user in order to tailor pop-up advertisements to target the user.

Spyware is not like a virus or worm in that it does not spread itself. Most spyware is installed

by the user, but usually without their knowledge. Typically users download desirable software

such as music players or file transfer programs upon which the spyware is piggybacked. Theend user license agreement (EULA) of the main program may inform the user of this bundling

of programs, but the notification is usually buried in the many pages of fine print that few read.

An example of this wasKazaa Lite, a file sharing application many downloaded for free and

installed without reading the EULA. Not only was this EULA 4 208 words long, but it

referenced nearly 20 000 words of contracts with other associated companies. Those who

ticked theI acceptbox agreed to amongst other things:

permitting their computer to be used as a server for others in their area allowing the usage of their computer and hard disc space to be sold onto other

companies

permitting spyware to be installed and then used to monitor their browsing habits allowing the spyware to look through their computer and report on the software

installed

not to use anti-spyware programs paying for legal costs in case of a lawsuit.

This information was buried in the contract. Few who read it would have agreed to the terms.Spyware can also be loaded onto a system when the user is tricked into doing something that

installs it without realising what they are doing. As mentioned earlier a Trojan horse is a

program that claims to do one thing but actually does another. The user downloads what is

described as a useful program (e.g. a web accelerator or software agent) and does not realise the

program really is spyware. A variation on this is where the user clicks on a link for a promised

action (e.g. optimising Internet access) which instead triggers the download of the spyware.



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One form of spyware is described as adware. This is software that displays adverts, either with

or without the users consent. Some users are prepared to put up with advertisements to obtain

a free version of a program. These are displayed as part of the normal operation of the program

and the user accepts them as the cost of ownership. A later upgrade to the paid version of the

program will remove the adverts.

In addition to covert monitoring of the user, spyware can also reduce the performance of the

infected system by tying up resources. These parasitic programs can cause the computer to

crash or hang.

There are programs to detect and remove spyware. In extreme cases of multiple infection the

whole system may need a fresh install.

Keystroke loggingKeystroke logging is a process of recording the keys a user presses on the computer keyboard.

While this can have legitimate purposes such as diagnosing typing habits, it can also be used to

detect passwords, encryption keys, or other confidential information such as banking details.

Keystroke logging can be carried out by either hardware or software.

Hardware loggers are either attached to the keyboard, and hence are easily spotted, or are

installed so that they are hidden inside the keyboard. Software loggers are more difficult to

spot, and may enter the computer through a virus, worm or Trojan horse.Both hackers and law enforcement agencies use keystroke loggers. The hackers use the

information gained to access password protected systems or for financial gain. The law

enforcement agencies use the loggers to track the activities of criminals or terrorists.

Denial of service attacksIn the normal course of events sites such as Googlereceive hundreds of millions of hits a day.

The number of hits determines the rates they set for advertising; the higher the number of visits

- the more they charge advertisers. However a site can have too many visitors. Sites such asNASA during a shuttle launch can receive so many hits that their servers may not be able to

keep up with demand.

In some cases there have been deliberate attempts to overload web servers. Unhappy

customers, cyber-vandals, or commercial competitors can take part in a denial of service (DoS)

attack. Using automated URL calls, a site can be bombarded with thousands of page requests a

second from dozens of locations. The demand can be so much that the web server is overloaded

and legitimate customers or users cannot get through. The web site is effectively shut down.

In some cases the perpetrators will use many other computers to assist in the DoS. Using aworm (such asBlaster) they secretly install remote access privileges on other peoples

computers. These infected machines can then be controlled by IRC and configured to act as a

group. When ready the zombie computers are activated and together bombard the targeted

server with many thousands of page requests. This form of attack is called a distributed denial

of service (DDoS) attack.

Such attacks have been made against many of the leading web sites. Originally there was

nothing that could be done after all web sites want visitors, but such attacks are now illegal.



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CookiesA cookieis a file used by the users Internet browser to identify the computer to a web site.

These are text files of information and are stored on the local HDD. (For Internet Explorer look

in Windows > Cookies; for Firefox use Tools > Options choosePrivacy and thenCookies and

View Cookies.)

The information stored by cookies includes such things as arrival time, pages visited, time

spent on the site, information the visitor has volunteered, searches made, and so on. The use of

cookies is mostly harmless and can be a help in speeding up access. It can also be used to greet

the user or to check identity at the next access.

However cookies can be misused. Some sites use the information stored to serve up adverts

based on previous accesses. In some cases the information collected can be used to helpdevelop a profile of the user. Some sites form cookie rings that share information.

Cookies can be disabled if the user is concerned about privacy issues but many sites require

access to the users cookie file before they can be visited. Without cookies enabled web access

would be severely limited. Browsers do give some control over cookie handling and there is

cookie management software and cookie eater software available to help the user to maintain

control.

Activ ity 9.3 Abusing the system1. a What is spam?

b Explain how the use of mailing lists is a privacy intrusion.

c Why is spamming so universally disliked?

d Why does it continue?

e What regulations or laws are there currently in force in Australia to control spam?

2. a Explain the difference between phishing and spoofing.

b What is an anonymiser and why might spoofers use one?

c What is the purpose of phishing? List some of the confidential information phishers

might seek.

d How would the flooding of unlistenable versions of a song discourage downloading

of a track?

e What is pharming, and why might someone pharm web addresses and redirect users?

3. a Why should users of the internet be wary of sharing personal or contact data?b In what ways can such data be supplied inadvertently?

c What aspects of web security should the home user employ to maintain privacy and

the integrity of their system?

4. Explain with examples the meaning of each of the following:

a Identity theft.

b User profile.



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c Social engineering.

d Cyber-bullying.

5. How might the originators of spyware make money?

6. Outline a scenario in which keystroke logging might be used.

7. a What might motivate a person or group to mount a denial of service attack on a

company or website?

b Research and report on an actual DoS or DDoS that has occurred

8. Identify both the positive and the negative aspects of cookies.

9. Many web sites publish a privacy policy.Either visit such a web site and briefly summarise their policy, or list the features you

think a web site privacy policy should include.

10. Visit the Electronic Frontiers Foundation at www.eff.organd identify their stand in regard

to on-line privacy. Check out also epic.organd www.privacyinternational.org.

Activity 9.4 Social issues report

Prepare a report on one of the social issues of information systems. This is to be written in theformat of a conventional report and based on your own research. It will detail the findings of

your investigation and will conclude with a commentary of how significant the issue is, and

what you see as its possible future ramifications.

Presentation is to be in the format of a report of at least 1 500 words. The initial preparation or

research may be done in pairs, but the report itself is to be written individually.

In developing the report you will follow the Information Literacy Cycle (ILC), which is a

variation on the DDE cycle.

IdentifySelect the social issue to investigate. Possible topics include:

the implications for privacy in a technological world misuse of the Internet, e.g. spam, spoofing, spyware, phishing, denial of service

attacks, on-line hate groups, cyberstalking (choose one or two only)

censorship or restriction of the Internet by government social networking, IRC/IM, gaming, wikis, blogs responsibilities in developing knowledge based systems biometrics using the computer to commit fraud, e.g. to steal money, or credit card information the changing workplace e.g. the virtual office, tele-commuting, e-business, e-banking the computer vandals: hackers or virus writers the effects of on-line computer games on individuals, or on society in general the sociological effects of computerised automation (job displacement, downsizing,

deskilling, relocation, social unrest, OH&S, etc.)



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technophobia (the fear of computers) industrial espionage in the computer industry obsessive behaviour and computers gender or socio-economic differences in relation to access, availability and utilisation

of computing resources

a related topic agreed to with your teacher

Determine informationWhen you have chosen a topic, briefly list the matters to include in the report. Use this list to

identify the information to find out or collect.

Determine methods of research and possible sources of information. These will include library

resources, computer magazines and journals, as well as on-line sources.

Prepare a list of suitable terms that will assist in focussing your search efforts.

The Information Literacy Cycle

Identify sourcesConduct some initial research to establish if you can find sufficient data to support a report on

your topic.

Select the resources most relevant to your topic.

Research the issue you have chosen. The information you collect must be factual, and based on

reputable and reliable sources.

Collect and organiseMake notes of relevant information found and carefully record bibliographical information. For

web sites this will include the access date in addition to the URL.

Read through your notes and select the parts of the research to use in your report.

Divide the information into logical sections. Choose headings and list the main points to be

presented in each section.


D l i i f i 331


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Prepare a draft of the main sections of your report and your commentary. This is to be

submitted to your teacher for advice, directions and suggestions at this stage.

Develop your draft into a report with the following sections:

Title page report title, your name, who the report is for, due date Table of contents section headings and page numbers Summary (50 words ) brief outline of what the report covers Introduction (150 words) explain the background to the report and specify its

purpose and scope; explain any specialist terms you will use

Body of the report (800+ words) relevant data concerning topic divided into logicalsections with suitable headings; write in paragraphs with a topic sentence and one

main idea to a paragraph Discussion (500 words) commentary on your findings (see below) Bibliography clearly indicate all sources of data Appendices (optional) additional information (e.g. tables of data).

ReflectionAs part of your report make a commentary on your findings. In this state the relevant

significance of the issue. How important is it, and how serious is its effect on society? Discuss

the potential future impact of the issue. Support your comments with reference to key points inyour report.

Conclude the report by making a recommendation on whether those involved should be

encouraged or dissuaded if necessary, and how.

To finish we are going

to see how intelligent

computers can be


9 Developing an Information System

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