Systems Development 1. Introduction a. How does a good system help organization? i. Employees: Better decision, increased productivity. ii. Agility: Change rapidly, flexibility. b. Why is systematic approach to systems development important? i. To manage risk ii. To manage time and cost iii. To avoid problems and pitfalls. 2. System Development LifeCycle a. 7 stages of systems development from start to finish. (PADDTIM) i. Planning: Determine goals, set objectives. ii. Analysis: Gather end user requirements iii. Design: Describing the desired features, screen layouts, business rules, pseudo code iv. Development: actual systems development v. Testing: test for errors vi. Implementation: start using vii. Maintenance: update, repair, and modify. 3. Software development methodologies a. Waterfall Methodology: Sequential. Second activity starts when first finishes. i. Oldest methodology: 30 years old ii. Success: 1 in 10 iii. Reason: Ignores uncertainty and creativity in new projects. A flaw in planning gets magnified by the time it reaches implementation. It assumes the users can clearly articulate and specify their requirements. iv. Managing costs, resources, and time constraints is difficult.b. Rapid application development (RAD): Also called rapid prototyping. i. What: Rapidly develop prototype of the system that looks like the actual system. ii. How: Involve system users in analysis, design and development. iii. Advantages: Accommodates faster pace of businesses, Accelerates systems development. c. Extreme programming: Divide the entire project into several independent pieces and then develop each piece using waterfall methodology. At the end of the day, all the pieces are put together and combined together. This allows intermediate deliveries of projects. IE and Netscape were developed like this. d. Agile Methodology: It is a form of extreme programming. i. Agile means fast and efficient, small and nimble, lower cost, fewer features, shorter projects. ii. Quick and continuous delivery of useful software components by reducing the coding and limiting project scope iii. Success 65%. iv. It is sort of a combination of rapid prototyping and extreme programming. v. How: Slash the budget (analogy: Invest small amounts in lot of different companies), cut your losses (if it doesn’t work book your losses), keep requirements at minimum (start with only the essentials), Test and deliver frequently (As often as a week so that errors are found in time), Assign non-IT executives (develops sense of ownership) 4. Systems development life cycle a. Planning: Establish high level plan, determine goals i. Identify/Evaluate the problem/Opportunity: A solution to a real problem can be very powerful. Google gives dedicated time to its employees to come up with new ideas. This step can generate a lot of ideas each of which requires commitment to limited resources. So selection is made based on critical success factor ( work on project that is critical to the success of the company). Some activities performed in this stage are value chain analysis, strategicalignment, Cost/Benefit Analysis, resource availability, project size/duration/difficulty. ii. Do project feasibility: financial, technical, economic, legal, operational, schedule, technical. iii. Develop a plan: Driving directions in a project. If you miss a turn, update the directions. b. Analysis i. Gather business requirements: What is the system supposed to do? Get a sign-off from the user. How: Joint application development, Individual interviews, survey employees, observe, review documents. ii. Create process diagrams: visually depict the processes described above to show flow of data. How: use dataflow diagrams (DFD). Make recommendations to change processes. iii. Build Vs. Buy c. Design i. Design the IT infrastructure: Infrastructure on which the system resides should be robust, scalable, economical, and adaptable. ii. Design the system models: Develop GUI, Data Models, ERDs. d. Development i. Develop the IT infrastructure: Purchase and implement the required equipment. ii. Develop the database and programs e. Testing i. Write the test conditions: Button click, add new customer, delete customer, enter negative amount, evaluate on Pass/Fail ii. Perform the system testing: Application testing, backup and recovery testing, integration testing, documentation testing, regression testing, unit testing, user acceptance testing. f. Implementation i. Determine implementation method: parallel implementation, phased implementation, pilot implementation, plunge implementation. ii. Provide training: Workshops, online modules, class rooms. iii. Document: Help manuals, user manuals, quick start guide. g. Maintenance i. Build help desk for support ii. Perform system maintenance: Adaptive maintenance, corrective maintenance, perfective maintenance, preventive maintenance. iii. Upgrade/Change 5. Software Problems and Business Problems Common errors: If project is running late, what do you think gets cut. a. Skipping SDLC b. Failure to manage project scope: Overestimate capabilities and underestimate time required.c. Failure to manage project plan: Imagine if you miss a turn and do not correct your course. d. Changing