Feasibility study A feasibility study is a preliminary

Feasibility study A feasibility study is a preliminary investigation of a problem. It is used to decide whether a solution is possible and what effects it might have. It includes the following -A description of the existing system -Success criteria -An outline of possible solutions -A proposed solution -A development plan -A cost/benefit anlysis

Other Aspects Technological feasibility. Economic feasibility Social effects Does the organisation have the people required to run the system • Effect on the client-benefits • •

Establishing the inputs, outputs and processing of an existing system Document Inspection helps establish the inputs and outputs

An Example-Payroll Systems • Identify the inputs • Explain the processing in detail • Identify the outputs

Recording the information about the current system It is very important because systems constantly evolve and programmers and analysts change. Data Flow Diagrams(DFDs) are used to graphically represent inputs, processing and outputs identified. DFDs consist of four components which are terminators(entities), processes, flow arrows and stores Draw the digrams Table 6. 1 and Figure 6. 3

Components Of A DFD • Terminator-somebody or somewhere outside the system from or to which data flows. • Process box(shown with a circle)-represents the processing • Data store(rectangle with no vertical sides)represents the data stored • Data flow(arrows)-each arrow is labelled to show the data moving • There are different levels of DFDs- starting from context level(level 0) which has few details, then level 1, level 2 etc

Systems Flow Chart • Another method that can also be used is a Systems Flow Chart but this is normally used in the Design stage • Draw Table 6. 2 and figure 6. 4

Examples of past scenarios

Requirements Specification • Add notes

Identifying problems with the current system • The diagrams above together with results from all the different fact finding methods are analysed in order to identify weaknesses • Appropriate methods of input and output are identified • Storage is also determined • Processor requirements are also determined • A requirements specification is produced(User, Hardware and Software requirements)

Design The following will be designed: • Inputs • Outputs • Files and/or Databases • Processing required • Validation • A test strategy • Hardware and software specification

Designing Data Collection Forms