View
219
Download
3
Category
Preview:
Citation preview
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-4
The Systems Development Life Cycle
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
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.
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-6
The Systems Development Life Cycle
Feasibility analysis and decision points
Conceptual Design
Evaluate design alternatives
Develop design specifications
Deliver conceptual design requirements
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-8
Conceptual Systems Design
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-9
Conceptual Systems Design
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-10
The Systems Development Life Cycle
Feasibility analysis and decision points
Physical Design
Design:output/database/input
Develop programs
Develop procedures
Design controls
Deliver developed system
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-12
Physical Systems Design
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-14
Physical Systems Design
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-15
Physical Systems Design
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.
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-16
Physical Systems Design
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-17
Physical Systems Design
– reconciliation of balances– database access– output preparation and distribution– computer operator instructions
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-18
Physical Systems Design Control design: What are some control design
considerations?– validity– authorization– accuracy– access– numerical control– audit trail– Security– Integrity
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-19
Physical Systems Design
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.
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-20
The Systems Development Life Cycle
Feasibility analysis and decision points
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-22
Systems Implementation
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.
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-23
Systems Implementation
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-24
Systems Implementation
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.
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-25
Systems Implementation
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.
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-26
Systems Implementation
Complete documentation: Three types of documentation must
be prepared for new systems.1. Development documentation
2. Operations documentation
3. User documentation
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-27
Systems Implementation
Test system: There are three common forms of
testing.1. Walk-through
2. Processing of test transactions
3. Acceptance tests
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-28
Systems Implementation
Conversion: There are four conversion
approaches.1. Direct conversion
2. Parallel conversion
3. Phase-in conversion
4. Pilot conversion
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-29
Systems Implementation
Old system
New system
Direct Conversion Method
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-30
Systems Implementation
Old system New system
Parallel Conversion Method
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-31
Systems Implementation
Phase-in Conversion Method
Old system
New system
Systems Implementation
Pilot Conversion Method
1 2 3 31 2
33 22 11
Old Old Old Old Old New
Old New New New New New
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-33
Systems Implementation
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-34
The Systems Development Life Cycle
Operation and Maintenance Operate system
Modify system Do ongoing maintenance Deliver improved system
SystemsAnalysis
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
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?
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-38
The Players
What are top management’s roles?– providing support and encouragement– establishing system goals and
objectives– determine information requirements
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-43
Planning Systems Development
Why is planning an important step in systems development?– consistency– efficiency– cutting edge– lower costs– adaptability
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-47
Feasibility Analysis
Economic feasibility is the most frequently analyzed of the five aspects.
What is the basic framework for feasibility analysis?– capital budgeting model
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-48
Feasibility Analysis
What are some capital budgeting techniques?– payback period– net present value (NPV) – internal rate of return (IRR)
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
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.
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-51
Behavioral Aspects of Change
How do people resist AIS changes?– aggression– projection– avoidance
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-52
Behavioral Aspects of Change
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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-53
Behavioral Aspects of Change
– 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
©2003 Prentice Hall Business Publishing, Accounting Information Systems, 9/e, Romney/Steinbart
Lecture 03-54
End of Lecture
Recommended