System Study :- Analyze and identify the problems, alternate solutions are evaluated, and a solution is recommended. Once the solution is accepted it requires resouces commitment.
Design:- Detailed design of the system is accomplished. Technical specification are prepared for all the tasks which includes Hardware software and personnel tasks.
Development:-The system is constructed as per design specifications. Computer programs are written. All manuals, software specification, and other documents are completed. Training and testing is finished.
Operation:- System is installed operated and maintained. The performance is reviewed, and necessary changes are made for the remaining life cycle time.
Prototyping is a technique for speeding up the development of computer information system by working with model which leads to the final system. It is beneficial where user involvement is high.
Product flow is the flow of raw materias into subassemblies, then into subassemblies and finally into finished goods, which is relativel easy to visualize.
e.g. Purchasing - (Vendor) - Receiving - Inventory - Production - distribtion (Customer) -sales - Billing - collection .
Information (or data) flow consiste of creation and movement of the administrative and operational documentation necessay for product flow.
e.g. Inventory - purchase requisition - Purchasing - P.O - receiving - inventory transfer - inventory.
Purchasing - P.O - vendor - invoice - approve - paring - check - vendor.
Communication involves interviews(make short, user,make sure user know the problem, take notes, explain that they know more than you,Thanks) , technical writing( Policies, Narrtive - intro, summaries problem statement, and background discussion) and presentation( select proper people, know the name of attenders, select easy title, make intangible tangible(reduction in cost,money), allow some time for discussion, make subject oriented jokes) During presentation use different charts Bar - for realtionship and comparison. Line - communicate movement. they can display trends curves or any ralationship. Pie - Better for presenting relationship as percentages Step - can be used inplace of line to convey a motion.
Joint application Design(JAD) approach is is emphasizes the importance of close, concentrated efforts by the designers of the system with the users of the system. Planning, scheduling and tracking progress of project is important and can be done using Gantt ,cost, and performance charts. In addition critical path and PERT charts are introduced for scheduling multiple activity projects.
Project management :- Identify roles and responsibilities of the system team. create project reviews package. Use Gantt chart to show the progress plan and actual progress in the meeting plan.
Use a line chart with a plot of the estimated costs and a plot of the actual costs as it incurred.
Dat flow Diagram (DFD) is a network that describes the flow of data throughout a system, data stores, and the processes that change or transform, data flow. A square represents a data source or entity, --> represent flow of data, A Circle or a bubble represent a process(all action verbs) the transform data streams. parallel line represent data store.
Decomposition is subdivision of high level DFD to lower-level DFD.
Data dictionary contains description and definition of all the system data structure.
Entity is any object , physical or abstract about which data are stored
E-R diagram is a diagram uses predefined symbols to identify entities and thge relationship among them.
CASE The upper CASE tools(study & design phase) focuse on analysis and design resulting in a set of design specification. Prototyping is a useful preliminary and detailed tool.
The Lower CASE product(development & operation phase) convert a detailed design specification into usable computer program 4GLs interface with the central repository to generate program source code.