Techniques to Elicit Requirements

A lire sur:  Tenstep

Requirements are usually gathered in two places during a traditional project. High-level requirements help you complete a Project Charter. Detailed requirements are gathered during an Analysis Phase. The detailed requirements help you understand how to design and build the solution. 

The TenStep requirements gathering model has four steps - elicitation, validation, specification and verification.

The elicitation step is where the high-level requirements are gathered. To elicit accurate requirements, the project manager must ask the right kind of questions and then listen carefully to the answers. Gathering requirements through an interview process is probably the most common technique. However, there are many techniques for gathering requirements, and in many projects the team will need to utilize a number of them instead of, or in addition to, interviewing. For instance, if you want to gather input from 100 users, you probably will not be able to talk to each one of them independently. In fact, if you did, you would find that you are not receiving very much information after you have finished the first couple. A better, faster and cheaper approach might be to interview a small number of people in this group and then send surveys to the rest.

There are a number of techniques for eliciting requirements, and your project may need to use multiple techniques depending on the circumstances. 

• One-on-one interviews. The most common technique for gathering requirements is to sit down with the clients and ask them what they need. The discussion should be planned out ahead of time based on the type of requirements you are looking for.
• Group interviews. These are similar to the one-on-one interview except that there is more than one person being interviewed. Group interviews require more preparation and more formality to get the information you want from all the participants. You can uncover a richer set of requirements in a shorter period of time if you can keep the group focused.
• Facilitated sessions. In a facilitated session, you bring a larger group together for a common purpose. In this case, you are trying to gather a set of common requirements from the group in a faster manner than if you were to interview each of them separately. 
• JAD sessions. Joint Application Development (JAD) sessions are similar to general facilitated sessions. However, the group typically stays in the session until the session objectives are completed. In this case, the participants would stay in session until a complete set of requirements is documented and agree to. 
• Questionnaires. These are much more informal, and they are good tools to gather requirements from stakeholders in remote locations or those that will have only minor input into the overall requirements. A questionnaire can also be a valuable way to gather quick statistics, such as the number of people who would use certain features, or to get a sense for the relative priority of requirements.
• Prototyping. Prototyping is a relatively modern technique for gathering requirements. In this approach, you gather preliminary requirements that you use to build an initial version of the solution – a prototype. You show this to the client, who then gives you additional requirements. You change the application and cycle around with the client again. This repetitive process continues until the product meets the critical mass of business needs, or for an agreed number of iterations.
• Following people around. This is especially helpful when gathering information on current processes. You may find, for instance, that some people have their work routine down to such a habit that they have a hard time explaining what they do or why. You may need to watch them perform their job before you can understand the entire picture. In some cases, you might also like to participate in the actual work process to get a hands-on feel for how the business function works today.

Knowing the stakeholders that will provide requirements will help you determine the right techniques to utilize to best meet your needs. You should select techniques that get you the most relative information and are best suited for the audience.