Steps, Tools, and Techniques Chapter 6 Systems Development
Transcription
Steps, Tools, and Techniques Chapter 6 Systems Development
Chapter 6 Systems Development Steps, Tools, and Techniques 1 Presentation Overview Seven Phases In The Systems Development Life Cycle Knowledge Workers and Their Roles In The Systems Development Life Cycle Why Systems Fail Selfsourcing Outsourcing Prototyping 2 Introduction Systems development life cycle (SDLC) - a structured step-by-step approach for developing information systems. Lets bake a cake 3 Seven Phases in the SDLC Phase 1: Plan Planning phase - involves determining a solid plan for developing your information system. Critical success factor (CSF) - a factor simply critical to your organization’s success. 4 Seven Phases in the SDLC Phase 1: Plan Project scope – high-level system requirements. Project scope document – written project scope Project plan – defines the what, when, and who Project milestones - key dates for deliverables. Project manager - an expert in project planning. definition. questions. 5 Seven Phases in the SDLC Phase 2: Analysis Analysis phase - involves end users and IT specialists working together to gather, understand, and document the business requirements for the proposed system. Business requirements - the detailed set of knowledge worker requests that the system must meet in order to be successful. 6 Seven Phases in the SDLC Phase 2: Analysis Joint application development (JAD) - knowledge workers and IT specialists meet, sometimes for several days, to define or review the business requirements for the system. Requirements definition document – prioritizes the business requirements and places them in a formal comprehensive document. Sign-off - the knowledge workers’ actual signatures indicating they approve all of the business requirements. 7 Seven Phases in the SDLC Phase 3: Design Design phase - build a technical blueprint of how the proposed system will work. Technical architecture - defines the hardware, software, and telecommunications equipment required to run the system. 8 Seven Phases in the SDLC Phase 3: Design Modeling - the activity of drawing a Graphical user interface (GUI) - the GUI screen design - the ability to model graphical representation of a design. interface to an information system. the information system screens for an entire system. 9 Seven Phases in the SDLC Phase 3: Design 10 Seven Phases in the SDLC Phase 4: Development Development phase - take all of your detailed design documents from the design phase and transform them into an actual system. 11 Seven Phases in the SDLC Phase 5: Test Testing phase - verifies that the system works and meets all of the business requirements defined in the analysis phase. Test conditions - the detailed steps the system must perform along with the expected results of each step. 12 Seven Phases in the SDLC Phase 6: Implement Implementation phase - distribute the system to all of the knowledge workers for use. User documentation - how to use the system. Online training - runs over the Internet or off a CD- Workshop training - is held in a classroom ROM. environment and lead by an instructor. 13 Seven Phases in the SDLC Phase 7: Maintain Maintenance phase - monitor and support the new system to ensure it continues to meet the business goals. Help desk - a group of people who responds to knowledge workers’ questions. 14 Knowledge Workers and Their Roles in the SDLC Your participation in the systems development process is vitally important because you are (or will be) a: 1. 2. 3. 4. Business process expert Liaison to the customer Quality control analyst Manager of other people User acceptance testing (UAT) – determines if the system satisfies the business requirements. 15 Why Systems Fail 20% of systems are successful, 80% of systems fail. Five primary reasons why systems fail include: 1. 2. 3. Unclear or missing requirements Skipping SDLC phases Failure to manage project scope 4. 5. Scope creep – project scope increases Feature creep – developers add extra features Failure to manage project plan Changing technology 16 Insourcing Three choices for building a system include: 1. 2. 3. IT specialists within your organization - Insourcing Knowledge workers such as yourself – Selfsourcing Another organization – Outsourcing Insourcing - IT specialists within your organization will develop the system. 17 Selfsourcing Selfsourcing (also called knowledge worker development or end user development) - the development and support of IT systems by knowledge workers with little or no help from IT specialists. On Your Own How Have You Selfsourced? (p. 303) 18 Selfsourcing The Selfsourcing Process 19 Selfsourcing Advantages: Improves requirements determination. Increases knowledge worker participation and ownership. Increases speed of systems development. Disadvantages: Inadequate knowledge worker expertise leads to inadequately developed systems. Lack of organizational focus creates “privatized” IT systems. Insufficient analysis of design alternatives leads to subpar IT systems. Lack of documentation and external support leads to short-lived systems. 20 Outsourcing Developing Strategic Partnerships Outsourcing - the delegation of specific work to a third party for a specified length of time, at a specified cost, and at a specified level of service. 21 Outsourcing The Outsourcing Process 22 Outsourcing The Outsourcing Process Request for proposal (RFP) - a formal document that describes in detail your logical requirements for a proposed system and invites outsourcing organizations to submit bids for its development. 23 Outsourcing Advantages: Focus on unique core competencies. Exploit the intellect of another organization. Better predict future costs. Acquire leading-edge technology. Reduce costs. Improve performance accountability. Disadvantages: Reduces technical know-how for future innovation. Reduces degree of control. Increases vulnerability of strategic information. Increases dependency on other organizations. 24 Prototyping Prototyping - the process of building a model that demonstrates the features of a proposed product, service, or system. Prototype - a model of a proposed product, service, or system. Proof-of-concept prototype - used to prove the technical Selling prototype - used to convince people of the worth of a feasibility of a proposed system. proposed system. 25 Prototyping The Prototyping Process 26 Prototyping Advantages: Encourages participation. Resolves discrepancies Gives a feel for the final system. Helps determine technical feasibility. Helps sell the idea of a proposed system. Disadvantages: Leads to the belief that the final system will follow shortly. Gives no performance indication. Leads the team to skip testing and documentation. 27