Workforce cross-training decisions in field service systems with two job types

When job types are heterogeneous in a multi-server service system, pooling servers to reduce system delay requires cross-training. Managers should balance a reduction in customer waiting time with high service costs and possibly reduced server efficiency due to cross-training. In a field service system with two job types and a fixed number of servers, the determination of the mix of dedicated and cross-trained servers is a critical managerial decision. We were motivated by a real field service situation to study a model where the objective is to minimize the sum of the average service costs and the customer delay costs per unit time. We use simulation to investigate the impact of various system parameters such as the number of servers, server utilization, and server efficiency on the optimal workforce mix

An Efficient Heuristic for Pooled Repair Shop Designs

An effective spare part supply system planning is essential to achieve a high capital asset availability. We investigate the design problem of a repair shop in a single echelon repairable multi-item spare parts supply system. The repair shop usually consists of several servers with different skill sets. Once a failure occurs in the system, the failed part is queued to be served by a suitable server that has the required skill. We model the repair shop as a collection of independent sub-systems, where each sub-system is responsible for repairing certain types of failed parts. The procedure of partitioning a repair shop into sub-systems is known as pooling, and the repair shop formed by the union of independent sub-systems is called a pooled repair shop. Identifying the best partition is a challenging combinatorial optimization problem. In this direction, we formulate the problem as a stochastic nonlinear integer programming model and propose a sequential solution heuristic to find the best-pooled design by considering inventory allocation and capacity level designation of the repair shop. We conduct numerical experiments to quantify the value of the pooled repair shop designs. Our analysis shows that pooled designs can yield cost reductions by 25% to 45% compared to full flexible and dedicated designs. The proposed heuristic also achieves a lower average total system cost than that generated by a Genetic Algorithm (GA)-based solution algorithm. - 2019, Springer Nature Switzerland AG.Acknowledgement. This research was made possible by the NPRP award [NPRP 7-308-2-128] from the Qatar National Research Fund (a member of The Qatar Foundation). The statements made herein are solely the responsibility of the author[s].Scopu

Maintenance service logistics

Capital goods, such as manufacturing equipment, trains, and Industrial printers, are used in the primary processes of their users. Their availability is of key importance. To achieve high availability, maintenance is required throughout their long life cycles. Many different resources such as spare parts, service engineers and tools, are necessary to perform maintenance. In some cases, e.g. for trains, also maintenance facilities are required. Maintenance service logistics encompasses all processes that ensure that the resources required for maintenance are at the right place at the right time. In a broader sense, it also includes maintenance planning and design-for-maintenance. We first discuss capital goods and the requirements that their users have, which leads us to basic maintenance principles and the structure of typical service supply chains. Next, various relevant decisions and supporting theories and models are discussed. Finally, we discuss the latest developments within maintenance service logistics