Software Requirements Analysis

Software requirement analysis is to make the feasibility analysis of software during software planning to be refined and refined, analyze various possible solutions, and assign to each software element. Demand analysis is the final step in the software definition phase, which is to determine what the system must accomplish, which is to put forward complete, accurate, clear and specific requirements for the target system.

For the requirements analysis, we most often use structured analysis methods, commonly used tools have data flow chart, data dictionary, structured English, decision table, decision tree and so on.

1, Data flow Diagram (DFD)

Example: a flow chart describing the bank withdrawal process

2, Data dictionary

A, with the flow chart

B, term description-defined by the named element in each flow chart

Cases:

3, structured English

A, English command verb

b, the name defined in the data dictionary

C, a limited number of custom words

D, the logical relation word if-then-else,case-of,while-do,repeat-until and so on composition

4, decision table

When applied to multiple logical relationships

Example: Check the invoice

5, decision Tree

Omit the unnecessary combination of conditions, is a special case of the decision table, the decision table when the data elements too many, the decision tree

Cases:

Software Requirements Analysis