Language peer sets for Diplans: Designed 1988 ↑ 1980s languages ↑ Fifth generation↑ Late Cold War↑
Diplans(ID:7929/)
alternate simple view
Designed 1988 Extension of the Petri net formalism to design social as well as procedural aspects of computation. (Holt pioneered the approach with the GP and ACSI-MATIC programs at UNIVAC and Moore School, from which this grew)
3.1 A Preliminary Example Consider a small project plan. Three parts are to be made, one of them in two versions. Then two assemblies are made, as indicated in the critical path method (CPM) diagram of Figure 1. In this diagram tasks are named by their key output, for example, task A produces part A. Task 2C produces 2 copies (or versions) of part C, destined for incorporation into two assemblies, AC and BC. These two assemblies, taken as a pair, constitute the end of the project. This diagram, representing the ?3 parts, 2 assemblies? project, may be put to various uses, for example, to develop a resource schedule and to consider the effect of alternatives on project goals. In so doing, all resource requirements and costs are accounted to the tasks. [...] [...] 3.3 Working the Example We are now ready to sketch a diplanner?s approach to the ?3 parts, 2 assemblies? example. The purposes are -To illustrate in this familiar setting how ?organization machine thinking? applies. -To distill coordination effort in pure form out of this plan by capturing a small quantity of that ?elusive something? mentioned in the Introduction. -To illustrate improved ability to express what matters. The diplanner?s first thought in considering the 3 + 2 tasks in the example is how they may be spatially located relative to one another. Certainly the diplan will be different if they are scattered over five continents than if they are colocated on a single factory floor. The producer of the CPM diagram in Figure 1 must also have been influenced by this issue, even though personal assumptions cannot be read unambiguously out of the resulting diagram. To match the diplanner?s frame of mind, we now assume that all five tasks are near to each other. The diplan will also reflect assumptions about the gross scales of these tasks relative to one another, as measured in space, time, personnel requirements, and so forth. Once again, Figure 1 suggests that the planner was thinking of tasks of comparable magnitude, but the diagram does not say so explicitly. Figure 4 shows an allocation of the five tasks to ?rooms? in a manner that will make the diplan to be constructed look as much as possible like the CPM diagram in Figure 1. Notes to this figure follow. -The passages BC-to-A and 2C-to-B are necessary because the C parts must be transferred from the site of their construction to the assembly sites. The three passages to the outside are only relevant to beginning and ending the project. (The parts in Room 2C could be transported via the ?Outside,? but that would enlarge the work arena covered by the plan.) -The intention of the CPM diagram cannot be carried out at all without a minimum of three rooms. This follows from the fact that the plan calls for the independent, not mutually interfering, execution of the three tasks. -Notice that the two drawings of the CPM and the floor plan constitute two parts of a single plan. Figure 5 shows the diplan result.
