  This paper presents a framework that guides the requirements engineer in the
implementation and execution of an effective requirements generation process.
We achieve this goal by providing a well-defined requirements engineering model
and a criteria based process for optimizing method selection for attendant
activities. Our model, unlike other models, addresses the complete requirements
generation process and consists of activities defined at more adequate levels
of abstraction. Additionally, activity objectives are identified and explicitly
stated - not implied as in the current models. Activity objectives are crucial
as they drive the selection of methods for each activity. Our model also
incorporates a unique approach to verification and validation that enhances
quality and reduces the cost of generating requirements. To assist in the
selection of methods, we have mapped commonly used methods to activities based
on their objectives. In addition, we have identified method selection criteria
and prescribed a reduced set of methods that optimize these criteria for each
activity defined by our requirements generation process. Thus, the defined
approach assists in the task of selecting methods by using selection criteria
to reduce a large collection of potential methods to a smaller, manageable set.
The model and the set of methods, taken together, provide the much needed
guidance for the effective implementation and execution of the requirements
generation process.
