Software Testing Strategies for Software Requirements and Design

Software requirements testing and software design testing are very important and must be taken seriously. Specifications of software requirements and design must be verified and validated before the implementation. Many individuals involved in design still find that some of the techniques available for these tasks are difficult and far from practical. This paper presents simple and very practical techniques for these tasks. The suggested techniques emerge from integrating three specification techniques, namely an informal specification technique (English language), a semi-formal specification technique (graphical models, namely entity-relationship diagram, data flow diagram, and data structure diagram), and a formal specification technique (a slightly extended version of the language Z). The three techniques mentioned above are very useful for different aspects and by using all of them in combination will provide practical and efficient techniques for the above mentioned tasks. However, by just simply using them as usual does not provide satisfactory results, therefore, we adapt and modify them to achieve software requirements and design specifying and testing techniques that are capable of providing satisfactory results. In this paper, we discuss: 1) how to draw the diagrams, we will suggest new ideas of how to draw the diagrams; 2) how to write formal specifications for software requirements and design, we will suggest new ideas of how to write formal specification using the extended Z specification language; 3) how to apply informal and formal proofs to verify and validate software requirements specification and software design specification; 4) the procedures of some of the tasks concerned. We do believe that the suggested techniques will be found useful, not too difficult, and efficient, especially for business information systems.