1 Management Information Systems Information Systems Development Chapter 10

2 This Could Happen to You Dee wanted to develop a blog for communication  Focused goal  Short time frame  Was successful because system was simple  Single contributor  No user training RFID at DSI more sophisticated  Vendors would need to place RFID chips  Computer program would be needed to process data

3 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?

4 Q1. Systems Development Systems analysis and design Process of creating and maintaining information systems  Development 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-shelf  Must be adapted to fit needs of business and people

5 系統開發與軟體開發的比較

6 MIS in Use: Thinking Big about Systems Development Large scale corporate information systems are more complex  Need 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

7 Q2. Major Development Challenges Difficulty of determining requirements Requirements change as system develops Scheduling and budgeting difficult to estimate  Change as scope changes Technology changes Diseconomies of scale  Brook’s Law

8 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 situations  Different requirements  Some systems wholly automated, others not  Use augmentation system to fill gaps

9 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

10 Phases in SDLC

11 Q4. Systems Definition (1) Define goals and purpose for new system  Must facilitate organization’s competitive strategy  Supports business processes  Improves decision making Determine project’s scope  May be delineated by users, processes, or facilities Assess feasibility of project  Cost  Schedule  Technical feasibility  Organizational feasibility

12 SDLC ：系統定位階段

13 Systems Definition (2) If deemed feasible, project team created from IT personnel and users  Managers  Systems analysts  Programmers and software testers  Users

14 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

15 Q5. Requirements Analysis Phase Determine and document features and functions  Interview 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

16 SDLC ：需求分析階段

17 Q6. Designing Components Develop and evaluate alternatives  Accurate requirements critical Hardware design determined by project team Software design depends on source  Off-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

18 SDLC ：元件設計階段

19 設計的程序、步驟

20 System must be built  Components constructed independently  Document and review System testing  Individual components tested  System integrated and tested Users must be converted to new system Q7. Information System Implementation

21 SDLC ：實作階段

22 Systems Testing Test plan  Sequences 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 testing  Future system users try out system on their own

23 System Conversion (1) Converting business activity from old system to new  Pilot 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

24 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

25 五元件的設計與實作

26 Q8. Systems Maintenance Fixing or adapting system  Need 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

27 SDLC ：系統維護階段

28 Q9. Problems With SDLC SDLC waterfall  Phases are not supposed to be repeated  Often teams have need to repeat requirements and/or design phases Difficulty in documenting requirements  Analysis paralysis or uncertain requirements Scheduling and budget difficulties  Multiyear projects difficult to properly schedule  Estimations on labor often produce insufficient budgets

29 Estimating is just theory Project managers sum up estimates and take to management Management then negotiates the schedule and budget  Every change will negatively impact the project Start with optimistic schedules and end up with late projects Guide: The Real Estimation Process

30 How Does the Knowledge from This Chapter Help You at DSI? You can now give a summary of the phases of SDLC  Describe tasks more specifically  Create a realistic schedule