Modeling Spatial and Temporal Relationships in Network Techniques

Existing and widely used scheduling techniques suffer from many shortcomings and drawbacks. These are mainly due to the oversimplifications made in the late 50s, early 60s to adjust these scheduling models to the available mathematical and IT tools. In this paper, these shortcomings of network techniques are collected and classified. Following this, a new general model can be defined using a new representation system that allows, for example:
• the use of loops for determining recurring activities,
• precedence relations with arrows at both ends for modeling the sequencing problem in construction,
• precedence relations that can be used to describe minimal and maximal spatial distances,
• decision nodes with or without probability, etc.The third point of the above list is discussed in detail; an algorithm is presented in order to define the start of the succeeding activities, when the intensity of the activities change and both spatial and time distances can be defined. The algorithm is presented with the help of a practical example; generalization can easily be done based on this.Resources are assumed to be unlimited throughout the paper unless explicitly stated otherwise. The main result of this research is a more general scheduling model that better fits the needs of project planners than the existing methods.