A Conceptual Model of Agreement Options for Value-based Group Decision on Value Management

A group decision must be made when a design process is conducted by more than one person. In this situation, negotiation plays an important role in many design decision. Value Management (VM) is one of design decision methodology in construction. By involving multi disciplines, collaboration and teamwork, negotiation becomes an important role on VM using a value-based group design decision. This paper provides an approach to develop a conceptual model of agreement options for group decision in building wall system selection using value criteria which are function and cost. The characteristic of value criteria has not been applied on previous researches. Existing models which are commonly accepted are optimization-based models, for example aggregation methods, but these are not able to solve the problem of value criteria on VM. Group decision needs to identify the goals that can be optimized and those that can be compromised in order to reach an agreement among decision makers. Agreement options are determined by identifying the potential decision makers followed by determining the optimal solution for each sub-group. Five stages are conducted to identify and determine agreement options as a conceptual model which are determining the weighting factor of criteria for each decision maker; grading alternative for each evaluation criteria; scoring every alternative for every decision maker; determining the optimal solution; and determining the fitness factor of an alternative solution The agreement option model is facilitated to better design decision. The model developed in this research can be used for any development research on group decision and negotiation in design process within the construction industry. Future research in the application of this methodology in many field of decision will build a wide range of knowledge to solve the theoretical and practical gap between automated design and automated negotiation.