background: the reliability and safety of gas refineries are strongly associated with the reliability of other parts of the system. defect and failure in one part of a system can cause total system breakdown or accident. the failure and damage in these equipment such as transformers and boilers results in not only the equipment damage and human injuries but also productivity reduction. the purp...

The requirement engineering is the process of collection of requirements and further, implements it to the software development process. It is important for every organization to develop quality software products that satisfy the user’s needs. To achieve this goal we have to apply requirement engineering practices in every step of software development process. We use requirement engineering pra...