Sequencing Knowledge for Construction Scheduling

This paper describes and formalizes knowledge utilized by skilled schedulers for sequencing construction activities. Although it is recognized that construction scheduling involves many tasks (activity identification, duration estimation, etc.), the focus here is limited to an understanding of a number of key activity sequencing principles. This paper provides a grammar or language that represents governing factors for construction activity sequencing. Four basic factors are identified and described in detail. The physical relationships that exist among the different building components is one of the factors. Another is the interaction of construction trades. Sequencing is also affected by the requirement of an interference‐free path for all the objects to be displaced around the job site at construction time. Code regulations are also relevant for determining the order of execution of certain activities. A discussion of the flexibility of these four different sequencing constraints and of their relation to time is also presented. Finally, a brief overview of a knowledge‐based prototype system that incorporates a few of the identified sequencing governing factors is provided.