Time-cost tradeoff in fuzzy critical path analysis based on (1 − α) × 100% confidence-interval estimates

Project crashing is a method for shortening the project schedule by reducing the time of one or more critical activities to less than its normal activity time. The objective of crashing is to reduce project duration while minimizing the cost of crashing, which is also known as time-cost tradeoff problem. The unknown or vagueness about the time duration for activities has led to the development of fuzzy critical path method and fuzzy time-cost tradeoff problem. In this paper, we introduce a fuzzy approach based on statistical confidence-interval estimates and a distance ranking method for (1 - alpha) fuzzy number levels. The primary result obtained from this study is a Theorem based on statistical confidence-interval estimates through which the fuzzy critical path and fuzzy time-cost tradeoff problems can be solved efficiently.