工程作業間除了固定的作業關係外，也存在不固定的作業關係。由於不固定的作業關係的存在，作業間的前置後續關係會隨專案進行而不斷改變。然而目前進度控制模式皆假設作業間的前置後續關係是固定不變的，因此排程者需要花費許多時間與人力去修正改變作業關係，以符合專案進行之現況。本文以內部裝修工程為例，探討具有不固定作業關係的作業間之施作順序排定原則與影響因素，並利用物件導向技術發展物件導向評核術( OERT ) ，修正傳統網圖與排程計算方法，提供排程者在不知道網圖全貌的情況下仍可進行排程計算，並於排程計算的同時，更新作業關係且提供作業之最早時程、最晚時程與浮時等資料。 The logic relationships among project activities have two types: fixed and varied. Fixed type activities proceed with a fixed sequence predefined before scheduling, while varied type ones proceed without a constant sequence. Instead, in the latter case, the actual activity sequence is determined based on a principle of activity ordering, which is to do with, for example, the resources available and the finish time of their predecessors. The scheduling of a project with varied type activities is more difficult than the ones with a fixed type. However, current scheduling methods, including bar chart, critical path analysis, and balance of line, ail neglect the analysis to the activities with varied type of logic relationships. The paper devises a methodology to solve this problem by making use of the object-oriented technology. Each activity is taken as an object, with necessary attributes and associated methods. Inheritance properties in the object-oriented system are employed to simulate the calculation of activity start and finish times. As a result, the methodology, called object-oriented evaluation and review techniques, can be used to modity the current scheduling methods to analyze the project scheduling for the activities with both fixed and varied types of activity relationships.
