Requirement gathering is an essential phase that every project goes through. Gathering requirements for the project is not an easy process. Business analyst need to invest some adequate amount of time get complete requirements from the client. There are some techniques in gathering the requirements as follows.
Interviews are the most common and widely used techniques of two types: one to one and group interviews. In interviews, business analyst directly interact with the client or group of clients to have a conversation about the project requirements. Usually, it start with some unstructured questions like casual discussion with the client to understand the current work environment. Later on, analyst uses some prepared and structured question to get the needed requirements. In interviews, business analyst can gather lot of information about the project but, it is a time consuming and expensive process to perform.
Unlike Interviews, Questionnaires are more informal used to gather input from huge number of people especially from remote locations. These are good tools to get requirements from the stakeholder, generally it is a paper or electronic approach to collect the needs and distributed among the stakeholders. Questionnaires are not time consuming and can gather lot of information from more number of people. But, only limited information with close ended question and difficulties with open ended questions. Moreover, there is no guarantee that people returns the questionnaire.
Prototyping is modern technique for requirements gathering. In this approach, several different prototypes are constructed using the available requirements and these prototypes are presented to the client to get additional requirements. This process need to be repeated around with the client until the project meets client requirements. Prototyping is the best technique when objectives are unclear and complex. Regular user involvement of client speed up the process and easy to visualize what solution may look like. On the other hand, due to regular cycles of prototyping, it is time consuming and more expensive process.
Document Analysis is another requirements gathering technique used to analyze the existing documents of the current system. Business analyst scrutinize the present documents to get adequate information about the requirements of the project. Analyzing the existed documents helps him to prepare some requirement validating questions. The problems with this technique is, documents does not always exist. If they does, they might not good and might be out of date.