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1. Introduction to Management Information SystemsChapter 6 System Development HTM 304
2. 2 What Systems to be developed Many different types of systems in the organization
3. 3 System Development Fundamentals System Development a process for creating and maintaining information systems (IS)
-- Also called System Analysis and Design (Dr. Fang & Kumar, Summer 2007)
Developing an IS involves all 5 components:
4. 4 Personnel Involved
5. 5 Video System Development
6. 6 Think Big About System Development Many students are new to the systems development process due to working with personal computer tools.
The scope of work is large with large-scale corporate information systems and may be global with different languages and cultures.
Management of resources is a critical success factor.
Comprehensive processes are required for project staff to follow and adhere to in order to successfully meet project and systems objectives.
7. 7 Think Big (cont) Three software sources
Off-the shelf-with adaptation
Major IS rarely off-the-shelf due to involvement of company people and resources
8. 8 System Development Is Challenging Systems development difficult and risky
Many projects never finished
Some projects finish 200-300% over budget
Some projects finish on schedule and within budget but dont meet the goals
9. 9 System Development Challenges Difficulties in determining requirements
Changes in requirements
Scheduling and budgeting difficulties
Diseconomies of scale
10. 10 Systems Development Methodologies There are many different system development processes
System Development Life Cycle (SDLC)
Rapid Application Development (RAD)
Object-oriented System Development (OOD)
Extreme Programming (XP)
Information Systems Differ
No single process works for all situations
11. 11 Scales of Information Systems
12. 12 The 5-Phase Version of SDLC in our book
13. 13 System Definition Phase Tasks Define project
Goals and objectives
Scope statement of work
Form a project team
In-house IT staff
Outside consultants and staff (as needed)
User representatives (management and staff)
14. 14 SDLC Requirement Analysis Phase
15. 15 Requirement Analysis Phase Tasks The most important phase in the system development process is determining system requirements.
If the requirements are wrong, the system will be wrong.
If the requirements are determined completely and correctly, then the design and implementation will be easier and more likely to result in success.
Seasoned and experienced system analysts know
how to conduct interviews to bring such
requirements to light.
16. 16 Obtain User Approval Before You Move-on Once the requirements have been specified, the users must review and approve them before the project continues.
The easiest and cheapest time to alter the information system is in the requirements phase.
Changing a requirement in the implementation phase may require weeks of reworking applications components and the database.
17. 17 Component Design Phase
18. 18 Component Design Phase Each of the five components is designed in this stage.
The team designs each of the five components by developing a list of alternatives.
Each alternative is evaluated against the requirements.
Typically the best alternative that meets the requirements is selected.
19. 19 Hardware Design Team determines specifications for hardware they want to acquire
Team NOT designing hardware
Typically, large company has some type of computer network infrastructure
20. 20 Hardware Networking Alternatives PC or LANs over public Internet
Point-to-point leased lines
Lease time on some type of PSDN
Create Virtual Private Network (VPN) over Internet
21. 21 Program Design Depends on program source
Off-the-shelf team must assess products and evaluate them against requirements
Off-the-shelf with alteration - team IDs products and assesses alterations
Custom-design programs team write specifications
(documentation) for program code
22. 22 Database and Procedure Design Database design
Convert database design to data model
If off-the-shelf DB, little design needed
Procedures must be developed for system users and operations personnel to follow
Procedures typically address
Normal processing: procedures for using the system to accomplish business tasks
Backup: user procedures for backing up data and other resources
Failure recovery: Procedure to continue operation when system fails and procedures to convert back to the system after recovery
23. 23 People Component -- Design of Job Descriptions Job descriptions needed for both users and operations personnel
New IS may require new jobs
Organizations may have to add new duties and responsibilities due to information systems changes and enhancements
24. 24 Implementation Phase
25. 25 Comparison of Design and Implementation
26. 26 System Conversion 4 ways to implement system conversion
Pilot Implement entire system on limited portion of the business
Phased- New system installed in pieces across organization
Parallel New system runs in parallel with old system for a while
Plunge Old system turned off and new system turned on immediately
27. 27 Maintenance Phase
28. 28 Information System Maintenance Either fixing system to make it do
what is expected
Or adapting system to changing requirement
29. 29 Problems with SDLC The most formal procedure to develop large IS project
Systems development seldom smooth
Sometimes need to crawl back up waterfall
Difficulty documenting requirements in usable way
Scheduling and budgeting difficult, especially for large projects with large SDLC phases
30. 30 Review of SDLC What are the five phases?
Which phase is the most important?
Briefly describe the five phases.
31. 31 Other Developing Methods Rapid application development (RAD)
Object-oriented systems development (OOD)
Extreme programming (XP)
32. 32 RAD
33. 33 RAD Extensive Use of Prototypes Extensive use of prototypes
A mock-up of aspect of new system and could be:
-- Form -- Report
-- Database Query --User Interfaces
34. 34 E-R modeling of the Data Form
35. 35 CASE Tools CASE: Computer-assisted systems engineering
36. 36 Summary of RAD Characteristics Design / implement / fix development process
Continuous user involvement throughout
Extensive use of prototypes
Joint Application Design (JAD)
Use of CASE Tools
37. 37 Object-Oriented Systems Development (OOD) Began after RAD mid 1990s
Driven by new program development method Object-Oriented Programming (OOP)
A series of diagramming techniques called Unified Modeling Language (UML) facilitates OOP development.
38. 38 Extreme Programming Emerging Technique Developing Computer Programs
Not useful for large scale development system requiring business processes & procedures (or at least not yet realized)
There are cases where organizations have used it successfully in developing application programs.
Three main characteristics
Just-In-Time (JIT) Design
39. 39 Compare Development Techniques