An approach for identifying the most likely activity sequence in a resource-constrained stochastic network

Abstract

The biggest concern of a project manager is to identify the proper sequence of activities during project planning and execution so that he or she can appropriately arrange the necessary resources under limited resource availability. The purpose of this article is to develop an approach for identifying the most likely activity sequence in a resource-constrained stochastic network. The approach consists of two stages. The first is a procedure to construct a scenario tree. In the procedure, we integrate a large enough number of sets of feasible activity sequences into a scenario tree. Each set of feasible activity sequences is generated by resource-constrained, deterministic project-scheduling problems with a configuration of randomly generated activity durations. The second stage is a backward-pruning procedure subsequently adopted to eliminate the worse branches from the scenario tree according to a specific objective function. This procedure leads to a reduced scenario tree, on which basis the most likely activity sequence can be easily identified. For demonstration purposes, a simple network example is considered.

在專案規劃和執行時專案經理最關切的是辨識出作業執行的適當順序 ， 如此專案經理可以在有限的資源下適當地安排必要的資源。 本研究目的是在資源限制下作業工期是不確定的專案環境下提出一個找出最可能作業順序之手法。 此手法包含兩個階段 ， 在第一個階段是發展一個程序以建構一個可呈現專案執行所有可能路徑的場景樹(scenario tree) ， 此程序首先是隨意地模擬產生數量夠多的固定工期的資源限制專案排程問題 ， 而每一個問題都可以產生一組可行的作業順序 ， 最後再將全部可行路徑整合成為一個場景樹。 接下來第二階段是採用倒退刪除程序 ， 此程序是依據某一特定的目標函數以刪去較差的分支後即可得到一個縮小場景樹(reduced scenario tree) ， 據此就可很容易辨識出專案最可能作業順序。 最後 ， 以一簡單專案網路案例實地示範說明。

(*聯絡人: [email protected])

Keywords:

• resource-constrained stochastic network
• most likely activity sequence
• scenario tree

Keywords:

• 關鍵詞： 資源有限隨機專案網路 ， 最可能作業順序 ， 場景樹

Notes

(*聯絡人: [email protected])