2. Modeling the decision-making process

Any decision is an action that can have an effect on actors, resources, constraints or objectives. Considering an objective as a target to be reached, a decision is a possible path (or process) towards this objective. A decision is therefore a process that leads an actor to answer a question.

Our model, the DTL, is sufficiently generic to apply to both product design decisions and decisions concerning the choice of actors. Variables can therefore represent products, projects, organizations, processes or resources, passing through all possible states (see "DTL representation" figure, step 1).

DTL is a model of the decision process. It considers a decision lifeline from the consideration of a question to the transmission of the answer.

The DTL comprises six phases:

• input...