For the fill criteria in our illustration, multiple objectives are used, one objective per period. This form of criteria distinguishes between the fulfillment levels of each period, and easily represents a situation where the fulfillment of jobs in one period is more important than in another period. For example, in some organizations, fulfillment of current jobs might be more important than fulfillment of future jobs; in other organizations, the opposite might be true. For our illustration then, if a t period model were developed, there would be a total of s=t+1 objectives, one for the fill criteria in each period and one for the overall fit criterion. In the MOEN model, the fill criteria are formulated as goal objectives: under- or over fulfillment is allowed, but minimized. In the illustrative example presented below, the relative importance of under filling and overfilling is equal. Again, this is appropriate for our example, but is not a requirement imposed by the structure of the MOEN model or the solution approach used. In fact, either under- or over fulfillment could be prohibited if that were necessary for a particular problem.