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Formulating Certain Scheduling Activities for Mixed Integer Programming

IP.com Disclosure Number: IPCOM000069475D
Original Publication Date: 1978-Apr-01
Included in the Prior Art Database: 2005-Feb-20

Publishing Venue

IBM

Related People

Authors:
Chen, RL Crowder, HP Held, M Johnson, EL Wolfe, PS [+details]

Abstract

In many scheduling models, such as for time-phased investment or installation of equipment, this condition must be met: if a unit activity is started in a particular time period, then that unit must be completed either (i) in the same, or (ii) in the following, time period. An activity for which (i) is always required is said to be of Type I; variables for Type I activities are required to have integer values. An activity for which we require only that either condition (i) or (ii) hold is said to be of Type II. While linear optimization problems involving variables of Type I are well handled by existing procedures for mixed integer programming (MIP), such as that employed by the IBM Program Product MPSX-MIP/370, no existing large-scale routine can directly handle an activity of Type II.