Info System Development 11 13 12 System development life cycle SDLC the way software systems are built Testing is a major source of difficulty SDLC basic 7 steps Systems Development Life Cycle PHASE 1 PLANNING Phase 1 Planning phase involves establishing a high level plan of the intended project and determining project goals Primary planning activities from a strategic point of view include 1 Identify and select the system for development 2 Specify Project Goals you need to have system built so you need to decide what best system to build is You have to have very specific goals that people can relate to so you can sell yourself to someone You need to make a good business case so someone will write you a check PLANNING 2 Assess Project Feasibility Feasibility study determines if the proposed solution is feasible and achievable from a financial technical and organizational standpoint have to demonstrate that this will actually work Different types of feasibility studies Economic feasibility study money Operational feasibility study Technical feasibility study Schedule feasibility study Cultural Organizational Change study Legal and contractual feasibility study Operational feasibility will system REALLY meet requirements if you say system will cut costs by 40 will it REALLY be able to do this a measure of how well a solution meets the system requirements Cultural or political feasibility building system implies changing way things work People resist change Examine your ability to get people who will use this system to accept the change a measure of how well a solution will be accepted in an organizational climate Technical feasibility can I really build the system Do I have the skills and competencies to do this Ex touch screen on iPhone they had to evaluate their ability to invent something new and get it to work reliably at a reasonable cost otherwise the whole thing goes out the window a measure of the practicality of a technical solution and the availability of technical resources and expertise Schedule feasibility can you really build it in timeframe Most people are too optimistic a measure of how reasonable the project timetable is Economic feasibility will this really return what I expect Need enough return for risk This is the one most people will look at a measure of the cost effectiveness of a project or solution Legal feasibility can I do this legally Will I run into a patent or contract issue a measure of how well a solution can be implemented within existing legal contractual obligations PLANNING 3 Develop the Project Plan Developing the project plan is a difficult and important activity The project plan is the guiding force behind on time delivery of a complete and successful system Continuous updating of the project plan must be performed during every subsequent phase during the SDLC Once you figure out goals you come up with a plan Plan should be continuously updated Systems Development Life Cycle PHASE 2 ANALYSIS Analysis phase involves analyzing end user business requirements and refining project goals into defined functions and operations of the intended system Primary analysis activities include 1 Gather business requirements 2 Create process diagrams system blueprint 3 Perform a buy vs build analysis Idea want to reduce my legal costs due to incorrectly dispensed drugs by 40 What does this mean Putting barcodes on prescription bottles What s the problem and what am I trying to solve This is the phase you start writing down the requirements How will you reduce by that 40 Need specific requirements that say this is what I m trying to accomplish ANALYSIS 1 Gather Business Requirements Business requirements the detailed set of business requests that the system must meet in order to be successful Different ways to gather business requirements Joint application development JAD session where employees meet to define or review the business requirements for the system take people involved in the process who WANT the new process and lock them in a conference room for a couple days and yell and have a brainstorming session then hopefully come out with a compromise that everyone s happy with difficult to get people to be locked up for 2 3 days Interviews Questionnaires Observations Review business documents The system users review the requirements definition document and determine if they will sign off on the business requirements Requirements definition document contains the final set of business requirements prioritized in order of business importance Sign off the system users actual signatures indicating they approve all of the business requirements ANALYSIS 1 Gather Business Requirements Business requirements are critical This is what the developer will use to build your system Requirements must be Clear Unambiguous Measurable Not dictate design Specific 1 reason of failure not specific enough Improve Customer Satisfaction is not a valid requirement You must be able to test it and say if it worked or didn t work ANALYSIS 2 Create System Model Diagrams Process modeling graphically representing the processes that capture manipulate store and distribute information between a system and its environment Common process modeling diagrams include Data flow diagram DFD illustrates the movement of information b w external entities and the processes and data stores within the system ER Diagrams data Event Diagrams Stimulus Response In analysis phase create initial diagrams to better understand the problem Blueprint is a set of drawings ANALYSIS 3 Perform a Buy vs Build Analysis An org faces two primary choices when deciding to develop an information system 1 Buy the information system from a vendor Commercial off the shelf COTS software package or solution that is purchased to support one or more business functions and info systems the cardboard box with the CD Not likely to do 100 what you want it to there will be things you don t like about it but is there enough you DO like or do you want to do a custom design so you get exactly what you want SCM CRM and ERP solutions are typically COTS 2 Build the information system 3 key factors an org should also consider when contemplating the buy vs build decision 1 Time to market obviously quicker to buy than build 2 Availability of corporate resources 3 Corporate core competencies do I have competencies to build this Systems Development Life Cycle PHASE 3 DESIGN Design phase involves describing the desired features and operations of
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