Effect of Machine Failure Prediction on Selected Parameters of Manufacturing Schedule in a Job-shop Environment

Abstract

Production scheduling involves a number of factors, which may disrupt or completely block the smooth operation of a production processes. This paper seeks to address one of the key factors involved, machine failure, which is capable of introducing disorganisation and nervousness into production. The relevance of machine failure to production is highlighted by the extensive research in the field of robust scheduling, as a method to absorb potential disruptions. The aim of this paper is to present technological machine failure prediction method to provide the base for a robust schedule, which is subsequently verified by the mathematical model. Furthermore, the paper elaborates on the issue of scheduling in job shop environment and the idea of robust scheduling. IntroductionJob scheduling in typical manufacturing systems is the subject of numerous analyses and research works. The research is predominantly focused on scheduling problems in job-shop environments due to the fact that this is the most popular and widely applied method of organising work in production companies [1]. A problem with much of the literature regarding job scheduling is that the work is frequently based on a set of simplifications, which determine that the character of such analyses is largely theoretical [2]. Consequently, a number of problems existing in an actual scheduling of manufacturing processes are disregarded. Practice shows that each production process involves a series of factors that are counter-productive to the realisation of the process itself [3]. One problem that should not be underestimated, as it shows great potential for disrupting production, is machine failure [4]. This paper takes a new look on robust scheduling of manufacturing jobs. The scope of the analysis included technological machine failure prediction and estimation of service times. The data for simulation was obtained from historical records from the Maintenance Department of a production company. Job-shop production systems Job shop environment characteristicsIn order to model a job-shop scheduling problem the following sets must be defined [5,6]:-M, which is a set of m machines processing the jobs: --J, which is a set of n jobs to be processed:Processing job Ji on machine Mj will be referred to as operation. Therefore what must be defined is [5,6]:

A Modified FMEA Approach to Predict Job Shop Disturbance

“…Second, equipment disturbances can certainly cause loss of capacity and throughput. Equipment failures cannot be underestimated since they are a common issue in most productive environments [16]. The pursuit of maximizing production benefits has led to machine overloading, accelerating equipment damages.…”