Systems Development and Analysis. ©2003 Prentice Hall Business Publishing, Accounting Information...

Systems Development and Analysis

©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart

Lecture 03-2

Introduction

This lecture discusses three topics:system development life cycle process of demonstrating the feasibility

of a new AIS behavioral aspects of change that

companies must deal with to successfully implement a new system


Lecture 03-3

The Systems Development Life Cycle

What are the five steps in the systems development life cycle (SDLC)?

1. Systems analysis

2. Conceptual design

3. Physical design

4. Implementation and conversion

5. Operations and maintenance


Lecture 03-4


Systems Analysis

Conduct initial investigation

Conduct system survey

Conduct feasibility study

Determine information needs and system requirements

Deliver systems requirements

Feasibility analysis and decision points


Lecture 03-5

Systems Analysis

When a new or improved system is needed, a written request for systems development is prepared.

The request describes the current system’s problems, why the change is needed, and the proposed system’s goals and objectives.

It also describes the anticipated benefits and costs.


Lecture 03-6



Conceptual Design

Evaluate design alternatives

Develop design specifications

Deliver conceptual design requirements


Lecture 03-7

Conceptual Systems Design

Evaluate design alternatives: The design team should identify and

evaluate design alternatives using the following criteria:

1. How well it meets organizational and system objectives

2. How well it meets users’ needs

3. Whether it is economically feasible

4. Its advantages and disadvantages


Lecture 03-8


Prepare design specifications: Once a design alternative has been

selected, the team develops the conceptual design specifications for the following elements:1. Output

2. Data storage

3. Input

4. Processing procedures and operations


Lecture 03-9


Prepare conceptual systems design report: At the end of the conceptual design a

conceptual systems design report is developed and submitted.1. To guide physical systems design activities

2. To communicate how management and user information needs will be met

3. To help assess systems’ feasibility


Lecture 03-10



Physical Design

Design:output/database/input

Develop programs

Develop procedures

Design controls

Deliver developed system


Lecture 03-11

Physical Systems Design

Physical design translates the broad, user-oriented AIS requirements of conceptual design into detailed specifications that are used to code and test the computer program.

Conceptualsystems design

Physicalsystems design


Lecture 03-12


Output design: The objective of output design is to

determine the characteristics of reports, documents, and screen displays.

Output fits into one of four categories:1. Scheduled reports2. Special-purpose analysis3. Triggered exception reports4. Demand reports


Lecture 03-13

Physical Systems Design File and database design: What are some file and database

design considerations?– medium of storage– organization and access– processing mode– maintenance– size and activity level– Security– Error Detection


Lecture 03-14


Input design: When evaluating input design, the

design team must identify the different types of data input and optimal input method.

What are the two principal types of data input?

1. Forms2. Computer screens


Lecture 03-15


Program design is one of the most time-consuming activities in the entire SDLC.

Programs should be subdivided into small, well-defined modules to reduce complexity.

What is this referred to as?– structured programming

Modules should interact with a control module rather than with each other.


Lecture 03-16


Procedures design should answer the who, what, where, and how questions related to all AIS activities.

What should procedures cover?– input preparation– transaction processing– error detection and corrections– control


Lecture 03-17


– reconciliation of balances– database access– output preparation and distribution– computer operator instructions


Lecture 03-18

Physical Systems Design Control design: What are some control design

considerations?– validity– authorization– accuracy– access– numerical control– audit trail– Security– Integrity


Lecture 03-19


At the end of the physical design phase the team prepares a physical systems design report.

This report becomes the basis for management’s decision whether to proceed to the implementation phase.


Lecture 03-20



Implementation and Conversion

Develop plan Install hardware and software

Train personnel, test the system Complete documentation Convert from old to new system

Fine-tune and review Deliver operational system

Systems Implementation

Implementation planning

Completedocumentation

Develop andtest software

programs

Conversion

Prepare site;install and

test hardware

Selectand trainpersonnel

Test system


Lecture 03-22


Implementation planning: An implementation plan consists of

implementation tasks, expected completion dates, cost estimates, and the person or persons responsible for each task.

Planning MAY include adjustments to the company’s organizational structure.


Lecture 03-23


Develop and test software programs: Seven steps are followed when developing

and testing software programs.1. Determine user needs

2. Develop a plan

3. Write program instructions (code)

4. Test the program

5. Document the program


Lecture 03-24


6. Train program users

7. Install and use the system Prepare site; install and test hardware: A PC requires little site preparation. A large system may require extensive

changes, such as environmental controls, UPS power and raised floor space.

Site preparation should begin well in advance of the installation date.


Lecture 03-25


Select and train personnel: Employees can be hired from outside

the company or transferred internally. Effective AIS training should include

employees’ orientation to new policies and operations.

Training should occur before systems testing and conversion.


Lecture 03-26


Complete documentation: Three types of documentation must

be prepared for new systems.1. Development documentation

2. Operations documentation

3. User documentation


Lecture 03-27


Test system: There are three common forms of

testing.1. Walk-through

2. Processing of test transactions

3. Acceptance tests


Lecture 03-28


Conversion: There are four conversion

approaches.1. Direct conversion

2. Parallel conversion

3. Phase-in conversion

4. Pilot conversion


Lecture 03-29


Old system

New system

Direct Conversion Method


Lecture 03-30


Old system New system

Parallel Conversion Method


Lecture 03-31


Phase-in Conversion Method

Old system

New system


Pilot Conversion Method

1 2 3 31 2

33 22 11

Old Old Old Old Old New

Old New New New New New


Lecture 03-33


Data conversion: Data files may need to be modified

in three ways:1. Files may be moved to a different

storage

2. Data content may be changed

3. File format may be changed


Lecture 03-34


Operation and Maintenance Operate system

Modify system Do ongoing maintenance Deliver improved system

SystemsAnalysis


Lecture 03-35

Operation and Maintenance

What are some factors to consider during the postimplementation review?– goals and objectives– satisfaction– benefits– costs– reliability– controls and security


Lecture 03-36

Operation and Maintenance

What are some questions to answer during the postimplementation review?– Does the system produce accurate

and complete data?– Is the system safeguarded against

unintentional errors, fraud, and unauthorized intrusion?

– Is the system documentation complete and accurate?


Lecture 03-37

The Players

Who are the people involved in developing and implementing AIS?– management– accountants– information systems steering

committee– project development team– systems analysts and programmers– external players


Lecture 03-38

The Players

What are top management’s roles?– providing support and encouragement– establishing system goals and

objectives– determine information requirements


Lecture 03-39

The Players What are accountants’ roles?

– determine their information needs– may be members of the project

development team– play an active role in designing

system controls– Assist with Cost / Benefit– Evaluate system including controls


Lecture 03-40

The Players

What are the steering committee’s roles?– set policies that govern the AIS in line

with corporate strategy– ensures top-management participation– guidance and control– facilitates coordination and integration

of IS activities


Lecture 03-41

The Players

What are the project development team’s roles?– plan each project– monitor project – make sure proper consideration is

given to the human element– Implement, test & train users


Lecture 03-42

The Players

What are the system analyst’s and programmer’s roles?– study existing systems– design new systems and prepare

specifications– write computer programs


Lecture 03-43

Planning Systems Development

Why is planning an important step in systems development?– consistency– efficiency– cutting edge– lower costs– adaptability


Lecture 03-44

Why Do Projects Fail?

1. Failure to establish Senior Mgmt Commitment

2. Taking shortcuts with System Development methodology

3. Unclear project expectations

4. Resistance to Change

5. Inadequate monitoring, reporting or controls

6. Not enough resources to complete project


Lecture 03-45

Why Do Projects Fail?

7. A project plan that is too simple, too complex or unrealistic

8. Imprecise objectives

9. Poor estimating techniques

10 Poorly trained analysts & programmers

11. Conflicting goals & objectives among project

team members & users

12. Use of inappropriate software or hardware


Lecture 03-46

Feasibility Analysis

What five important aspects need to be considered during a feasibility study?

1. Technical feasibility

2. Operational feasibility

3. Legal feasibility

4. Scheduling feasibility

5. Economic feasibility


Lecture 03-47


Economic feasibility is the most frequently analyzed of the five aspects.

What is the basic framework for feasibility analysis?– capital budgeting model


Lecture 03-48


What are some capital budgeting techniques?– payback period– net present value (NPV) – internal rate of return (IRR)


Lecture 03-49

Behavioral Aspects of Change

Individuals involved in systems development are agents of change who are continually confronted by people’s reaction and resistance to change.

The best system will fail without the support of the people it serves.


Lecture 03-50

Behavioral Aspects of Change Why do behavioral problems occur?

– personal characteristics and background

– manner in which change is introduced– experience with prior changes– communication– disruptive nature of the change

process– fear


Lecture 03-51


How do people resist AIS changes?– aggression– projection– avoidance


Lecture 03-52


How can behavioral problems be improved?– meet needs of the users– keep communication lines open– maintain a safe and open atmosphere– obtain management support– allay fears– solicit user participation


Lecture 03-53


– provide honest feedback– make sure users understand the system– describe new challenges and opportunities– reexamine performance evaluation– avoid emotionalism– present the system in the proper context– control the users’ expectations– keep the system simple


Lecture 03-54

End of Lecture

Systems Development and Analysis. ©2003 Prentice Hall Business Publishing, Accounting Information...

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Transcript of Systems Development and Analysis. ©2003 Prentice Hall Business Publishing, Accounting Information...