An integrated production and delay-time based preventive maintenance planning model for a multi-product production system

Abstract

integrated production and delay-time based preventive maintenance planning model for a multi-product production system. eksploatacja i niezawodnosc - Maintenance and Reliability 2015; 17 (2): 215-221, http://dx.doi.org/10.17531/ein.2015.2.7. customer orders and tactical planning. In this paper, our focus is on the medium-term tactical production planning, since at this level the production quantities or lot sizing should be determined, and the preventive maintenance (PM) decisions should be scheduled. Throughout this paper, we will use the term 'production planning' instead of 'tactical production planning', for simplicity.Production and maintenance departments are usually located separately in modern companies. The production department has to make production planning based on the maximum production capacity, and to satisfy customers' demands, whereas the maintenance department has to ensure the proper functioning of the production system through maintenance actions. Conflict is inevitably generated since the two departments share the same system. If the production department ignores the occupation of maintenance time, or just considers it subjectively or empirically, the system may experience idle time, production delays and even shortages. On the other hand, if the maintenance department schedules the maintenance without considering the produc- Xuejuan Liu Wenbin WAng Rui PengAn integrAted production And delAy-time bAsed preventive mAintenAnce plAnning model for A multi-product production system model integrujący plAnowAnie opArtej nA pojęciu czAsu opóźnieniA konserwAcji zApobiegAwczej orAz plAnowAnie produkcji dlA systemów produkcji wieloAsortymentowej

An integrated preventive maintenance and production planning model with sequence‐dependent setup costs and times

“…We just need to validate E C ( m ), which is derived on the basis of assumptions (1) and (2) from Section 2.1. We therefore need to explain the reasonability of these 2 assumptions . As described in Section 1, typical production systems are equipped with many components, so we use the complex system delay‐time model in this paper.…”

“…As we described in Section 1, in every period, some products need to be produced in lots with sequence-dependent setups; that is, the products must be produced in order. We use an ordered set s n ¼ i n 1 ; …; i n k ; ⋯; i n z À Á to denote a sequence n, in which there are z products and these products are different from each other on the basis of assumption (8). i n 1 i n k ; i n z À Á denotes the first (kth, last) product of s n , and the total setup time and setup cost of s n can be given by D n s ¼ ∑ , respectively, where d ij s (c ij s ) is the average setup time (setup cost) from product i to product j.…”

“…We therefore need to explain the reasonability of these 2 assumptions. 8 As described in Section 1, typical production systems are equipped with many components, so we use the complex system delay-time model in this paper. An approximation was made on the basis of the delay-time concept for complex systems: The defect arrivals from all components are grouped and modeled by a stochastic point process, such as an HPP, and the delay times of all defects follow one identical distribution.…”

“…We must find some approaches to prune the searching tree instead. Assumption (8) in Section 2.1 indicates that the singlelot problem is considered in this paper. At present, only Haase and Kimms 10 have used the SO method to solve the single-lot problem.…”

“…However, all these researches implicitly assumed that, in each period, the downtime caused by failures was calculated over the length of the period, allowing the system capacity in each period to be calculated before they solved the integrated model. In contrast, Liu et al used the real production time within the period, rather than the length of the period, to calculate the downtime caused by failures. This made the integrated model more complicated.…”