Performance evaluation for cost estimators by reliability interval method

Most consultant selection models stress the importance of past performance. However, there are so far very few studies on evaluating consultant's performance. It hampers the whole process of the selection model. This paper tries to establish a systematic approach in developing a consultant's performance evaluation model for the evaluation of the performance of cost estimators in the construction industry of Hong Kong. Nominal group technique is adopted in identifying the decision criteria for the evaluation, and a reliability interval method (RIM) is developed to assess the importance weighting of each criterion. The RIM allows statistical analysis and fuzzy assessment of the weight. The results report the weights of each decision criterion and its subcriterion in evaluating cost estimator's performance. Interestingly, the results show that traditional functions of cost estimator are the least treasured from the clients. Proactive and professional advice is considered to be much more important. The study is highly relevant to industry practitioners in assessing performance of costs estimators, as well as to researchers in further developing the consultant selection model.