**After years of working on complex operational problems,
it became clear that we needed a new vocabulary for modeling these
applications. The standard paradigm of deterministic math programming
was too rigid. Other approaches for integrating uncertainty, such
as stochastic programming, discrete dynamic programming and stochastic
control, were too difficult to apply to these problems. In engineering
practice, most people end up turning to simulation, which is extremely
flexible, but the lack of sophistication creates a host of practical
problems.**

**Given this need, we created a problem called a DRTP (Dynamic
Resource Transformation Problem). We pronounce these "DRiPs"
because we have implemented this modeling paradigm in Java, and
this pronunciation allows us to refer to the package as "DRiP
Java" (if you think this is bad, stay tuned). Also, DRTP
is hard to pronounce.**

**There are three dimensions of a DRTP: Information entities,
processes, and controls. We use the notation:**

Information || Processes || Controls

**to label a problem. Each of the three primary dimensions
has several subdimensions which together completely specify a
DRTP.**

**The problem class is fully described in the paper:**

Powell, W.B., J. Shapiro and H.P. Simao, “A Representational Paradigm for Dynamic Resource Transformation Problems,” Annals of Operations Research on Modeling (C. Coullard, R. Fourer, and J. H. Owen, eds), Vol. 104, pp. 231-279, 2001.

**To see a powerpoint presentation on DRTP's, click
here.**