Negative weights in network time model

作     者：Zoltan A.VATTAI Levente MALYUSZ Zoltán A.VATTAI;Levente MáLYUSZ

作者机构：Faculty of ArchitectureBudapest University of Technology and EconomicsMuegyetem rkp.3H-llll BudapestHungary 

出 版 物：《Frontiers of Engineering Management》 (工程管理前沿（英文版）)

年 卷 期：2022年第9卷第2期

页      面：268-280页

学科分类：1201[管理学-管理科学与工程(可授管理学、工学学位)] 08[工学] 0812[工学-计算机科学与技术（可授工学、理学学位）] 

基　　金：This work was supported by the Hungarian National Research Development and Innovation Fund(TUDFO/51757/2019-ITM Thematic Excellence Program).Open access flinding provided by Budapest University of Technology and Economics 

主　　题：graph technique network technique construction management scheduling 

摘      要：Time does not go backward.A negative duration,such as“time periodat first sight is difficult to *** network techniques(CPM/PERT/PDM)did not support negative parameters and/or loops(potentially necessitating recursive calculations)in the model because of the limited computing and data storage capabilities of early *** Roy and John Fondahl implicitly introduced negative weights into network techniques to represent activities with fixed or estimated durations(MPM/PDM).Subsequently,the introduction of negative lead and/or lag times by software developers(IBM)apparently overcome the limitation of not allowing negative time parameters in time *** to general digraph(Event on Node)representation where activities are represented by pairs of nodes and pairwise relative time restrictions are represented by weighted arrows,we can release most restraints in constructing the graph structure(incorporating the dynamic model of the inner logic of time plan),and a surprisingly flexible and handy network model can be developed that provides all the advantages of the above-mentioned *** paper aims to review the theoretical possibilities and technical interpretations(and use)of negative weights in network time models and discuss approximately 20 types of time-based restrictions among the activities of construction *** focus on pure relative time models,without considering other restrictions(such as calendar data,time-cost trade-off,resource allocation or other constraints).