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Management Information SystemsManagement Information Systems

Information Systems Development

Chapter 10

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This Could Happen to You

Dee wanted to develop a blog for communicationFocused goal

Short time frame

Was successful because system was simple Single contributor

No user training

RFID at DSI more sophisticatedVendors would need to place RFID chips

Computer program would be needed to process data

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Study Questions

Q1. What is systems development?

Q2. Why is systems development difficult and risky?

Q3. What are the five phases of the systems development life cycle?

Q4. How is systems definition accomplished?

Q5. What is the user’s role in the requirements phase?

Q6. How are the five components designed?

Q7. How is an information system implemented?

Q8. What are the tasks for systems maintenance?

Q9. What are the problems with SDLC?

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Q1. Systems Development

Systems analysis and design

Process of creating and maintaining information systemsDevelopment involves all five components

Requires more than programming or technical expertise Human relation skills

Business knowledge

Understanding of group dynamics

Information systems are never off-the-shelfMust be adapted to fit needs of business and people

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系統開發與軟體開發的比較

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MIS in Use: Thinking Big about Systems Development

Large scale corporate information systems are more complexNeed to ensure all employees are working toward same goals

Must develop system that will function consistently in different languages

May need to store information on worldwide use of product and the relevant laws

Most information systems are process-design oriented

Must be carefully planned and executed

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Q2. Major Development Challenges

Difficulty of determining requirements

Requirements change as system develops

Scheduling and budgeting difficult to estimateChange as scope changes

Technology changes

Diseconomies of scaleBrook’s Law

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Q3. Systems Development Processes

Methodologies:Systems development life cycle (SDLC)

Rapid application development (RAD)

Object-oriented systems development (OOD)

Extreme programming (XP)

No single process works in all situationsDifferent requirements

Some systems wholly automated, others not Use augmentation system to fill gaps

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SDLC

Classical process with five phases:Systems definition

Management’s statement defines new system

Requirements analysis Identify features and functions

Component design Based on approved user requirements

Implementation Implement, test, and install new system

System maintenance Repair, add new features, maintain

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Phases in SDLC

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Q4. Systems Definition (1)

Define goals and purpose for new systemMust facilitate organization’s competitive strategy

Supports business processes

Improves decision making

Determine project’s scopeMay be delineated by users, processes, or facilities

Assess feasibility of projectCost

Schedule

Technical feasibility

Organizational feasibility

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SDLC：系統定位階段

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Systems Definition (2)

If deemed feasible, project team created from IT personnel and usersManagers

Systems analysts

Programmers and software testers

Users

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Ethics Guide: Estimation Ethics

Buy-ins Companies agree to produce products for less than it

knows will be required “Time and materials” contracts

Fixed-cost contracts

In-house projects are often started with buy-ins Projects started with hopes of more money later

Team members may disagree about costs

Not all costs may have been included in estimate

Also may have buy-in on schedule

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Q5. Requirements Analysis Phase

Determine and document features and functionsInterview users

Document requirements Examine existing system

Review reports, forms, queries, application features

Security and controls

Approve requirements

Less expensive to change system in this phase

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SDLC：需求分析階段

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Q6. Designing Components

Develop and evaluate alternativesAccurate requirements critical

Hardware design determined by project team

Software design depends on sourceOff-the-shelf

Off-the-shelf with alterations

Custom-developed programs

Data model converted to database design

Procedures designed for BI system

Job descriptions created for users and operations personnel

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SDLC：元件設計階段

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設計的程序、步驟

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System must be built Components constructed independently

Document and review

System testingIndividual components tested

System integrated and tested

Users must be converted to new system

Q7. Information System Implementation

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SDLC：實作階段

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Systems Testing

Test planSequences of actions that users take when employing system

Both normal and incorrect actions should be considered

Labor intensive

Product quality assurance (PQA)Testing specialists

Beta testingFuture system users try out system on their own

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System Conversion (1)

Converting business activity from old system to newPilot installation

Organization implements entire system on single, limited unit

If systems fails, it only affects limited boundary

Reduces exposure

Phased installation New system installed in phases

Tested after each phase

Continues until installed at entire organization

Can’t be used in tightly integrated systems

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System Conversion (2)

Parallel installation New system runs in parallel with old system during testing

Expensive and time consuming

Data must be entered twice

Provides easy fallback position

Plunge installation Direct installation

Install new system and discontinue old

There is no backup position

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五元件的設計與實作

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Q8. Systems Maintenance

Fixing or adapting systemNeed method to track system failures and

enhancements

Corrections usually prioritized based on severity

Enhancements usually prioritized based on business decision

Must generate reasonable rate of return

Decision to restart systems development process

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SDLC：系統維護階段

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Q9. Problems With SDLC

SDLC waterfallPhases are not supposed to be repeated

Often teams have need to repeat requirements and/or design phases

Difficulty in documenting requirementsAnalysis paralysis or uncertain requirements

Scheduling and budget difficultiesMultiyear projects difficult to properly schedule

Estimations on labor often produce insufficient budgets

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Estimating is just theory

Project managers sum up estimates and take to management

Management then negotiates the schedule and budgetEvery change will negatively impact the project

Start with optimistic schedules and end up with late projects

Guide: The Real Estimation Process

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How Does the Knowledge from This Chapter Help You at DSI?

You can now give a summary of the phases of SDLCDescribe tasks more specifically

Create a realistic schedule