1 / 30

Systems Development

Systems Development. Planning Lifecycle. Systems Development: Some Key Questions. How does an organization ensure that its IT resources support its business plan? How do we ensure compatibility and interoperability across different system development efforts?

benjamin
Download Presentation

Systems Development

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Systems Development Planning Lifecycle

  2. Systems Development: Some Key Questions • How does an organization ensure that its IT resources support its business plan? • How do we ensure compatibility and interoperability across different system development efforts? • How does a systems project get authorized? • How is a project controlled and reviewed?

  3. Systems Lifecycle • Investigation • Design • Construction • Testing • Implementation • Maintenance • Enhancement • Retirement All of these activities comprise system development and form a lifecycle

  4. Strategic Planning • Based upon businesses multiyear strategic plan • Identify IT components or requirements within the business plan • Include IT inhibitors as well as IT-based breakthroughs • Create rough plan of major IT initiatives • This should form a baseline IT plan as well as human resources plan

  5. Steps in IS Planning Strategic Plan Identify Projects Prioritize and Select Determine resources required (people, $, time) Create planning document

  6. 3-Year Business Plan Accelerate product intro process to 4 months Move manufacture of mature products to Mexico Expand e-commerce capabilities to direct online selling and custom catalogs 3-Year IS Plan Engineering automation: implement e-only design process Extend corporate network to offshore manufacturing partners Create internet sales site and custom catalog framework Example

  7. Example The objectives of this plan must be time sequenced and budgeted

  8. Architecture • Many firms have developed “systems architectures” • A high-level roadmap which maps business functions to present and future systems • And shows relationships between systems • Does not specific timeframe • Must be updated regularlyl • Specific investment decisions and priorities can be made within this framework

  9. Discussion: The benefits of an architecture • Situation

  10. Systems Development Model • Traditional • Alternatives • Prototyping • Rapid Application Development • CASE-based • Time-boxing

  11. Benefits of Methodology • Various models are often called “methodology” • A system of methods • Provide common language and expectation • Allow for standard management reviews • Create standards for documentation and testing • Almost impossible to be credible without one

  12. Traditional Software Development Lifecycle (SDLC) • Often called Waterfall Model Investigation Design Construction Implement

  13. Traditional SDLC • From four to 12 phases • One phase completed before beginning next phase • Emphasis on documentation and checkpoints • Detailed planning and budgeting at each phase

  14. Example of SDLC Phase and Deliverable • Pre-investigation • Project proposal and recommendation • Investigation • Investigation Report • Analysis of alternatives • Cost and benefit analysis • Schedule • Recommendation • Requirements Analysis • Detailed system requirements • Revised cost and benefits analysis • Revised schedule

  15. Example of SDLC Phase and Deliverable • Design • Logical design • Technical design • Test plans • Revised cost and benefits analysis • Revised schedule • Construction & Testing • System elements • Implementation plans • Contingency plans • End user training materials • Maintenance plan • Operations plans • Implementation • Cutover / Phase in

  16. Pros and Cons of SDLC • Advantages • Lends itself to good control • Phase deliverables well defined • Facilitates contracting • Clear checkpoints makes reviews easy • Creates detailed documentation which is valuable for maintenance

  17. Pros and Cons of SDLC • Disadvantages • Time and cost estimation difficult • Can be very slow • Requires that requirements are defined abstractly, without interaction with “system” • Overall ownership usually on “systems” people

  18. Improvements to Traditional SDLC • Dedicated project teams • Full time end-user designers • JAD workshops • Joint Application Design • Facilitated workshops • 1 to 5 days • Scribes • Perhaps prototype tools • Requirements definition or design

  19. Time Box Approach • Identify objectives • Create project team • Set time period (6 weeks) • Team cycles through all phases of lifecycle very quickly, sometimes in parallel • Fast development tools very useful • Review takes place at end of time period • Continue project for another period? • Cancel all-together? • Implement current system?

  20. Advantages of Time Box Approach • Advantages • Eliminates gap between system on paper and “real” system • Immediate demonstration of technical feasibility • Limits investment risks • Developers prefer it

  21. Disadvantages of Time Box Approach • Disadvantages • Longer commitment may be needed to get results • Danger of implementing unstable or poorly-maintainable product • Without discipline to focus on objectives, can be wasteful

  22. Prototyping • Aim: Quickly create something that shows how the system (or a portion of it) will work • Allow hands out interaction with system to test requirements and key design features • Problem: How do you build something quickly? • Use 4GL (fast development, poor performance), recode later • Reduce feature set (no editing of data) • Create key modules only

  23. Prototyping • Nonoperational prototypes • Mockups that don’t really work • Limited to input and output (reports, screens) • Operational prototypes • Working systems or portions of systems • Possibly 4GL based

  24. CASE Tools • Computer Aided Software Engineering • Toolsets to speed software development and improve quality • Upper CASE • Focus on investigation, analysis and design • Lower CASE • Design, code generation and testing • Integrated CASE include both

  25. CASE Tools • Repository • Database containing all development objectives • Data elements and definitions • Requirements • Code modules • Enables a team to work on the CASE project • Data model • Dictionary and schema • Code generation • Product 3GL or 4GL code

  26. Rapid Application Development • Trendy term for many of these alternative methods used is some combination • CASE • JAD • Prototyping • Time Boxing

  27. Project Management • Project Management • Identification of tasks to be completed • Understanding of relationship between tasks • Tracking of task ownership and status • Adjustment of resources and plans in reaction to events • Task tracking and accountability • Management reporting and escalation

  28. Risk Assessment • Many projects predictably fail do to risk profile • Major risk factors • Scope • Timeline • Experience of team • Organizational change • Geographic scope

  29. End User Development • Easy-to-use tools encourage end-user development • So does IT department resource constraints • Advantages • Good knowledge of business needs • Control of resources and priorities • Disadvantages • Lack of technical expertise • Lack of planning

  30. IT Organization vs. End-User Development • Source of tension • Users: “It is too slow and don’t know our business” • IT: “Users produce poor systems and leave us with maintenance” • How should IT respond to this? • Ignore • Outlaw and drive underground • Offer assistance and consultation

More Related