Abstract

In today's rapidly changing manufacturing industry, even minor uncertainties can cause significant disruptions for small and medium-sized enterprises (SMEs). Although previous studies on operational supply chain networks have focused primarily on addressing uncertainties related to demand fluctuations, machine breakdowns, and unpredictable events such as natural disasters and geopolitical disruptions, this paper specifically addresses workforce uncertainty due to stochastic turnover rates. As an extension of the multistage workforce capacity planning problem with turnover proposed by \cite{2007Successive}, this study builds on their workforce planning network, which incorporates decisions around transferring, hiring, and firing, by introducing a proficiency ranking system. This system classifies the workforce into three proficiency levels, each with a specific production rate according to the worker's status. Integrating this proficiency ranking system into the planning network allows a more comprehensive evaluation of workforce capabilities to meet the required demand. Results from numerical experiments demonstrate that the modified model offers an optimized workforce planning solution, balancing cost and time effectively, to help SMEs achieve their demand targets under conditions of uncertain workforce turnover.