摘要:

Contractor prequalification involves evaluation of factors that contain a high degree of uncertainty. Current methods of contractor prequalification fail to address uncertainty in the evaluation process. The use of fuzzy sets is examined to address this shortcoming. Fuzzy sets have been employed in order to provide a more consistent, rational method of evaluating the non-random uncertainties that are present in the contractor evaluation process. The linguistic factors (such as good, fair, or poor) used in fuzzy set analysis provide a more appropriate means to model decision circumstances that occur in industry than the current crisp (usually numerical) factors. Evaluation factors from a previous study are used. Each factor was assigned a grade. Correspondingly, each grade was represented by a fuzzy set. These fuzzy sets were then weighted and combined resulting in a fuzzy set. This composite fuzzy set represents the contractor's rating. When evaluating multiple contractors, each contractor's composite rating is rank ordered to allow the project owner to select the most desirable contractors to participate in the bidding process.

ISSN:0263-0257    

DOI:10.1080/02630259408970134

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

This paper presents a resource allocation algorithm for construction planning and control. The algorithm integrates the use of experience, decision-making criteria, a utility/cost matrix, an optimization procedure and a resource-smoothing heuristic. First, a planner uses his/her experience and the optimization procedure to develop several scheduling alternatives for reallocating a resource that is limited for a given interval (period-1) during the execution of a project. Next, the planner selects the best scheduling alternative by using the utility/cost matrix, where he/she can set performance goals and their relative importance according to his/her experience and company policy. Finally, the planner uses the optimization procedure and the resource-smoothing heuristic to reschedule the available resource efficiently within the remaining part of the project (period-2). The suggested method provides the user with a feasible solution that meets preset scheduling standards and planning criteria and accounts for the circumstances at the time the decision is made.

ISSN:0263-0257    

DOI:10.1080/02630259408970135

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

This paper integrates the concepts of grey systems and fuzzy sets into optimization analysis by dynamic programming as a means of accounting for system uncertainty. The developed grey fuzzy dynamic programming (GFDP) model improves upon previous DP methods by allowing uncertain input information to be directly communicated into the optimization process and solutions through the use of different a-cut levels of fuzzy numbers for the input fuzzy information, and the use of a grey fuzzy linear programming (GFLP) method for an embedded LP problem. The modelling approach is applied to a hypothetical problem for the planning of waste flow allocation and treatment/disposal facility expansion within a municipal solid waste management system. The solutions of the GFDP model corresponding to different a-cut levels provide optimal decisions regarding different development alternatives in a multi-period, multi-facility and multi-scale context, as well as the upper and lower limits of waste flow allocation. The results indicate that reasonable and useful solutions can be achieved through the developed GFDP approach.

ISSN:0263-0257    

DOI:10.1080/02630259408970136

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

ISSN:0263-0257    

DOI:10.1080/02630259408970137

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

ISSN:0263-0257    

DOI:10.1080/02630259408970138

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor