Introduction

This capability describes how TASK_METHOD, TASK_METHOD_VERSION and TASK_ELEMENT can be associated to other parts of the PLCS data model.

The specification of a TASK_METHOD is not merely a matter of saying "do this, then this", but needs to be linked to the resources needed - skilled personnel, tools, equipment, spare parts, and so on. A TASK_METHOD is one of the poles about which PLCS turns, and so, unsuprisingly, is the centre of a complex network of associations. The raw model merely asserts that these relationships may exist, but that a relationship may be given a specific meaning by classifying it, where the classification is held as reference data. The aim of this capability is to explore the legitimate meanings of these relationships, and provide the basic reference data needed. This will provide a template for implementations, which may replace or -better - extend the reference data.

A TASK_METHOD is the centre of a large network of associations, through characterization, usage,TASK_METHOD_ASSIGNMENT, TASK_METHOD_VERSION_ASSIGNMENT and TASK_ELEMENT_ASSIGNMENT and by relationships between TASKMETHODs, between TASK_METHOD_VERSIONs and between TASK_ELEMENTSs. This capability systematically works through this network, identifying the meanings of the of each association, and providing the reference data needed to distinguish alternative meanings.

The characterizations of TASK_METHOD, TASK_METHOD_VERSION and TASK_ELEMENT are out of scope, being covered by REPRESENTING_TASK and REPRESENTING_TASK_STRUCTURE respectively. The meaning and characterization of TASK_METHOD_ASSIGNMENT, TASK_METHOD_VERSION_ASSIGNMENT and TASK_ELEMENT_ASSIGNMENT are in scope, and covered below. In particular, the allocation of a RESOURCE to a TASK_METHOD, TASK_METHOD_VERSION or TASK_ELEMENT is considered in detail. The relationships to STEP from TASK_METHOD, TASK_ELEMENT and TASK_OBJECTIVE are considered separately in REPRESENTING_TASK_AND_STATE.

The association of a property to a TASK_METHOD , TASK_METHOD_VERSION and TASK_ELEMENT is discussed, and a default set of reference data is provided. Specific templates are provided for basic cost and time properties

The relationships of a TASK_METHOD to another TASK_METHOD, a TASK_METHOD_VERSION to another TASK_METHOD_VERSION and TASK_ELEMENT to anotehr TASK_ELEMENT are discussed, and a basic set of reference data is provided.

These associations are also considered in the light of the TASK_METHOD life cycle, and as to whether they form part of the definition of the TASK_METHOD or not. Detaled discussion of the life cycle is found in REPRESENTING_TASK.