Modeling the Maintenance Time Considering the Experience of the Technicians

Abstract

Typically, maintaining a machine requires two different distinct tasks: to select which components to focus their attention; and the subsequent task is to check, repair or replace the selected components. For both tasks, the experience of technicians plays a critical role. An experienced technician is likely to select fewer components and requires less time for the subsequent task compared to an inexperienced technician. As a result, the maintenance time will be varied depending on the experience of the technicians. Extant research for maintenance has predominantly used exponential distribution family for modeling primarily because of its analytical tractability but at the cost of fidelity and inability to capture important characteristics such as technicians' experience. With the growing adoption of networked sensors based on Internet of Things (IoT), big data, and real-time machinery diagnostics using artificial intelligence it is imperative to develop models with better fidelity for maintenance operations. Therefore, in this paper, we explore a model based on using the negative-hyper geometric distribution for maintenance time that varies based on the technicians' experience. Our proposed approach requires more inputs such as (1) number of components, (2) number of components not in working state (3) technician's experience level, and (4) time to fix a component based on the technicians' experience. For instance, input for (2) could be obtained from IoT sensors and diagnostics. We study the efficacy of the proposed model using computer simulations and statistically characterize the possible impact of technician experience on the parameters of the maintenance distribution.

Evaluating Technicians’ Workload and Performance in Diagnosis for Corrective Maintenance

“…The expected number of attempts for the group that did not use any diagnosis support system can be estimated using negative hyper-geometric distribution, since it is a similar process to the "trial-and-error" process [50] and it utilized eight attempts; this number of attempts could also be achieved when the other groups strictly followed the recommendations of the support systems and made no errors. The mean number of maintenance attempts of the group that did not use the support systems was 6.60 attempts, with a standard deviation of 1.92.…”

“…Time to complete mainly depended on two factors [50]: the number of maintenance attempts and the time spent on diagnosing, repairing, or replacing a component.…”

“…4.1. The Difference in Time to CompleteTime to complete mainly depended on two factors[50]: the number of maintenance attempts and the time spent on diagnosing, repairing, or replacing a component.If the number of diagnosis attempts is significantly different between groups, the…”