Technical Report Number
We discuss the problem of representing utility in planning systems that are based on Allen's  popular ontology for planning, which represents actions and events as time intervals. We identify a small number of primitive functions on time intervals which may be helpful in representing preference and also in eliminating dominated actions. Assuming that utility can be decomposed to take advantage of these primitives, these functions provide one solution to the problem of specifying utility in such expressive planning languages. We identify a restricted class of utility expressions that generate linear programming problems. The contribution is not deep, but is instructive. We conclude with the pessimistic observation that any extension to the Allen framework to support DMUR destroys much of the initial appeal of the system. What remains is the ontological emphasis on intervals. It may yet be appealing to some who find the ontology cognitively concordant, but it forces the introduction of a metric that Allen had originally sought to avoid.
Loui, R. P. and Chen, Jersey, "Clothespins on Timelines: Utilities and The Interval Representation of Time" Report Number: WUCS-93-5 (1993). All Computer Science and Engineering Research.