Lecture IS331812/3/12

Figure 6-6Microsoft Access has a rudimentary data dictionary capability that displays information about the size, format, and other characteristics of each field in a database. Displayed here is the information maintained in the SUPPLIER table. The small key icon to the left of Supplier_Number indicates that it is a key field.

Microsoft Access Data Dictionary Features

The Database Approach to Data Management

Some Drawbacks…• Complexity

• A DBMS is a complex piece of software all users must fully understand it to make use of its functionalities

• Cost of DBMS• The cost varies significantly depending on the environment and

the functionality provided. Must take into consideration recurrent annual maintenance costs

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Continued..

• Cost of Conversion• Cost of converting existing applications to run on the

new DBMS and hardware. (additional training costs)

• Performance • DBMS is written for applications in general which

means that some applications may run slower than before

• Higher Impact of Failure • Centralization of resources increases vulnerability of

the system4

Database Administrator • Oversees a staff of database specialists• Final recommendations for DB design• Load and maintain DB• Establish security controls• Perform backup and recovery

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Data Administration

Database Management

System

Data planning and modelling

technology

Database technology

And management

Data Administrator

Users

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Systems Analyst

• Or business analyst is a systems analyst that specializes in business problem analysis and technology-independent requirements analysis.

• A programmer/analyst (or analyst/programmer) includes the responsibilities of both the computer programmer and the systems analyst.

• Other synonyms for systems analyst include:• Systems consultant

• Systems architect• Systems engineer• Information engineer• Systems integrator 7

Role of the Systems Analyst

• Study problems and needs of an organization• Determine best approach to improving

organization through use of:• People• Methods• Information technology

• Help system users and managers define their requirements for new or enhanced systems

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Skills of a Successful Systems Analyst

• Analytical• Understanding of organizations.• Problem solving skills• System thinking

• Ability to see organizations and information systems as systems• Technical

• Understanding of potential and limitations of technology.

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Skills of a Successful Systems Analyst

• Managerial• Ability to manage projects, resources, risk and change

• Interpersonal• Effective written and oral communication skills

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System Owners

System owners are the information system’s sponsors and chief advocates. They are usually responsible for funding the project to develop, operate, and maintain the information system.

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System UsersSystem users are the people who use or are affected by the information system on a regular basis—capturing, validating, entering, responding to, storing, and exchanging data and information. A common synonym is client.

Types include:• Internal users

• Clerical and service workers• Technical and professional staff• Supervisors, middle managers, and executive

managers• Remote and mobile users (internal but disconnected)

• External users12

Stakeholders: Players in the Systems Game

• A stakeholder is any person who has an interest in an existing or new information system. Stakeholders can be technical or nontechnical workers.

• For information systems, the stakeholders can be classified as:• System owners• System users• Systems analysts• System designers• System builders• IT vendors and consultants

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Systems Development Lifecycle(SDLC)• The systems development life cycle (SDLC) model

is an approach to developing an information system or software product that is characterised by a linear sequence of steps that progress from start to finish without revisiting any previous step.

• The SDLC model is one of the oldest systems development models and is still probably the most commonly used.

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SDLC

• Traditional systems development lifecycle (Waterfall Model)

• SDLC - very similar to a product life

cycle in the consumer market because both a new product and information system develop through a number of stages.

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• The typical SDLC has the following steps:• Initiation• Feasibility study• System Investigation• System Analysis• Systems Design• Implementation• Review and Maintenance

• These stages are frequently referred to as “conventional systems analysis”, “traditional systems analysis”, “the systems development life-cycle” or the Waterfall Model

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SDLC or The Waterfall Model

• The waterfall model describes a development method that is linear and sequential.

• Once a phase of development is completed, the development proceeds to the next phase and there is no turning back.

• The advantage of waterfall development is that it allows for departmentalisation and managerial control.

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The Waterfall Model Continued..• A schedule can be set with deadlines for each

stage of development and a product can proceed through the development process and theoretically, be delivered on time.

• Development moves from concept, through design, implementation, testing, installation, troubleshooting, and ends up at operation and maintenance.

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Initiation

Analysis

Investigation

Implementation

Design

Maintenance

Traditional SDLC

NO FEEDBACK!!!!

SDLC

• This is now regarded as the “hard” systems approach because of its rigid demarcation between phases.

• It has shortfalls which lead to a number of difficulties

• One major criticism of the model is that it doesn’t cater for revisiting previous phases to correct defects.

• Feedback Loop – refinement of Waterfall Model

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Potential Strengths of the Traditional SDLC• It has been well tried and tested

• Use of documentation standards

• Following the methodology should aid (At least to some extent) that roll out dates, budgets and expected benefits are met.

• At the end of each phase, all parties involved in the project can review progress.

• Much greater control on the development of computer applications and make possible the use of project management tools and techniques 21

Potential Weaknesses of the Traditional SDLC

• Criticisms of the methodology or perhaps of the way it was used include:• Failure to meet the needs of management• Unambitious systems design• Instability• Inflexibility• User dissatisfaction• Problems with documentation• Lack of control

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Potential Weaknesses of the Traditional SDLC• Incomplete systems• Application backlog• Maintenance workload• Problems with the “ideal” approach• It does not allow for much reflection or revision.

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Prototyping• Building an experimental system rapidly and inexpensively for

end users to evaluate

• It will be refined until it conforms to the users’ requirements

• This is achieved through iterative development

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Advantages of Prototyping• Useful when there is uncertainty about system requirements

or systems design

• Valuable for End-user interface design

• Encourages end-user involvement throughout the systems development lifecycle

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Disadvantages of Prototyping• Better suited for smaller application development.

• Prototyping may mean glossing over essential steps in the system development.

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Application Software Packages• A set of prewritten, precoded application software programs

that are commercially available for sale or lease

• Packages have increased as many applications are common to many businesses: payroll, accounts and inventory control

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Advantages of Software Packages

• Most of the design work has been completed in advance

• Little extensive testing required

• Vendor support and maintenance

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Disadvantages of Software Packages

• Disadvantages may be increased with a complex system

• Required customisation and additional programming may be expensive

• Hidden implementation costs

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End User Development

• The development of information systems by end users with little or no formal assistance from technical specialist

• It has been made possible by fourth generation software tools (4GL)

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Encouraging End User Development

• The variety of application development tools available make it easier for end user development

• Guidelines for managers to encourage intranet website development by end users: • Look for what makes sense• Spur creativity• Set some limits• Give managers responsibility• Make users comfortable 31

Advantages to End User Development

• Improved requirements determination

• Increased user involvement and satisfaction

• Reduced application backlog

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Risks of End User Development

• It occurs outside the traditional mechanisms for information system management and control

• Problems in ensuring that end-user developed applications meet organisations objectives and standards

• Rapid systems development without a formal methodology may mean that testing and documentation is inadequate

• Loose control of organisational data33

Definition - Outsourcing• The practice of contracting computer centre operations,

telecommunications networks, or application development to external vendors

• Example: Bank of Ireland, Dell

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Outsourcing

• Outsourcing has become increasingly popular as companies believe that it is more cost effective than maintaining their own IS staff

• Many companies are outsourcing software procurement and support to application service providers (ASPs) who provide and support business application and other software via the Internet and intranets to all of a company’s employees workstations 35

Benefits of Outsourcing

• To reduce work in the information systems department.

• When the IS function within an organisation is limited.

• To improve the contribution of IT to enhance business performance.

• To create new sources of revenue.36

Benefits of Outsourcing

• To reduce work in the information systems department

• When the IS function within an organisation is limited

• To improve the contribution of IT to enhance business performance

• To create new sources of revenue37

Risks associated with Outsourcing

• May loose control over IS function

• Heavy reliance on the vendor

• Proprietary information may be leaked to the competition if sensitive data is available outside the organisation

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Sample Questions• Discuss Porter’s Competitive Forces Model, considering the

role of information systems in gaining competitive advantage. Illustrate your answer with diagrams and examples.

• Outline and briefly explain the stages involved on the SystemsDevelopment Lifecycle (SDLC).