In our modern society, software has become a very critical component in all kinds of systems and software failures have become the most vital factor that terminates the service and proper function of the whole system. Therefore, it is very important and urgent to understand the software development process and eliminate as many potential problems in software as possible.
Software reliability is defined as the probability of failure-free software operation for a specified period of time in a specified environment.
The determination of software reliability indices is the primary task in the software reliability engineering. The indices are taken as not only the basis for the software reliability design and the constraints during the software development process, but also the foundation of the software’s acceptance.
Software reliability indices are usually divided into Quantitative Indices and Qualitative Indices.
Quantitative indices are quantified software reliability parameters’ values, such as software reliability is quantitatively defined as the probability of failure free operation of a software program for a specified time under specified conditions. However, having a “number”, even with the appropriate accompanying evidence, is not generally sufficient to convince customers or even the system/software suppliers that the software satisfies its requirements. Thus, qualitative indices such as software reliability is also qualitatively defined as a set of attributes that bear on the capability of software to maintain its level of performance under stated conditions for a stated period of time.
A Study method for determining the software reliability qualitative indices based on the two standards of SAE-JA1003 and RTCA DO-178B which are widely used by the airworthiness and industrial sectors, as well as the best practices and management experiences of software reliability engineering.
Software reliability is quantitatively defined as the probability of failure free operation of a software program for a specified time under specified conditions.
Quantitative indices Factors:
1). Executive Support
2). Experienced Staff
Software reliability is also qualitatively defined as a set of attributes that bear on the capability of software to maintain its level of performance under stated conditions for a stated period of time.
The qualitative indices can be regarded as the requirements for software reliability activities throughout the development process. Unfortunately, currently there is no systematic theory and approach for software reliability indices’ determination.
This study proposes the method’s principle, which determines the software reliability qualitative indices according to the all stages of the software life cycle and the factors are divided into following requirement categories:
- Environment requirements
- Technique requirements