Feasibility study
- Five areas discussed: 1. economic feasibility
2. Technical feasibility
3. operational feasibility
4. Legal feasibility
5. Feasibility time
To identify the problem : to understand the problem has been resolved, and how these issues raised; how to solve in order to meet the requirements; understand the problem structure.
Market Research : understand the market the same software; demand
Analysis Preparation : Determine analysis plan (development plans, personnel); trainers; assignments
Environmental Analysis : hardware interfaces; Operating Environment; users know
- Software plan: 1 software range: functional size, hardware requirements, the complexity of the interface
2. Environmental resources: human resources, hardware, software, schedule, software costs
Resource Performance Description: What is the performance of the hardware and software to people and what level
- Software price estimation: parametric algorithms, source code line estimates, task decomposition, automatic cost estimate method
- Cost \ benefit analysis
Objective: top-down (first estimation system in estimating sub)
Bottom-up (first estimate for each module in the system cost of the overall synthesis)
Task feasibility study is to use the smallest cost to determine whether the problem can be solved in the shortest possible time.
Feasibility study does not apply to solve the problem but the problem is worth solving.
Funds accounted for 5-10% of project cost
demand analysis
Software requirements analysis tasks: in-depth description of the function and performance of the software
Interface to determine the details of the design constraints and with other system elements
The effectiveness of other requirements definition software
It is the logic of the model by means of the current system of export logical model of the target system, the target system to solve "the problem of what to do."
- Requirements analysis process
1. problem identification: Review Software Software appreciated range
Determine software requirements
Tips to achieve conditions and criteria
2. Analysis and Synthesis
From the information flow and information architecture, functionality and refinement of each element links, interfaces and design constraints
3. Develop the requirements analysis phase document
Software requirements specification, data requirements specification, preliminary user manual implementation plan
4. Requirements Analysis Review
Clear documentation is complete, whether important interface description, development risks
- Needs analysis principles: 1. Before starting analysis model, to understand the problem
2. Develop prototype enables users to understand how human-computer interaction occurs
3. Record the origin and cause of each requirement
4. The use of a plurality of views demand
The priority given to demand
- Requirements specification principles: separation from reality function, namely to describe "what" rather than "how to achieve";.
2 requires the use of process-oriented description language specifications (or system definition language)
- Software analysis principles: 1. Determine the function and information
2. Refinement of the problem stratified
- Decomposition: Decomposition lateral, longitudinal decomposition
- Structured Analysis :( data flow diagram, a data dictionary)
A method is for the data stream requirement analysis
2. suitable for the type of data processing software needs analysis
