Optimum workforce scheduling under the (14, 21) days-off timetable

Hesham K Alfares

doi:10.1155/s1173912602000123

Abstract

An efficient optimum solution is presented for a real-life employee day-soff scheduling problem with a three-week cycle. Over a given work cycle, each worker is given 14 successive workdays and 7 successive off days. This three-week days-off timetable is referred to as the (14, 21) schedule. Given different labor demands for each day of the week, the primary objective is to minimize the number of workers. The secondary objective is to reduce transportation cost by minimizing the number of active days-off patterns. The solution technique utilizes the dual LP solution to determine the minimum number of workers and feasible days-off assignments, without using linear or integer programming. The simple solution technique eliminates the need to use integer programming for this particular scheduling problem.

Highlights

Employee scheduling is a complicated multiple-objective problem, involving such diverse considerations as varying manning requirements, costs, availabilities, skills, and personal preferences
The solution presented in this paper is vastly simpler, and it produces the minimum number of active days-off patterns
An efficient optimum solution technique has been presented for scheduling employees using a real-life days-off schedule with a three-week cycle

Summary

Introduction

Employee scheduling is a complicated multiple-objective problem, involving such diverse considerations as varying manning requirements, costs, availabilities, skills, and personal preferences. Each employee is assigned one work stretch of 14 consecutive workdays and a break of 7 consecutive days off. This is an actual work schedule used by a major oil company to schedule employees in remote areas. The primary objective of the (14, 21) days-off scheduling problem is to minimize the workforce size, i.e., total number of employees assigned. In order to reduce transportation cost, we must add a secondary objective, which is that of minimizing the number of active days-off patterns (i.e., patterns to which some employees are assigned).

Literature Survey

Mathematical Programming Models

The Minimum Workforce Size

Days-Off Assignments

Conclusions