Many manpower planning models assume age to be normally distributed. In this paper we have examined the suitability of beta distribution for age. Beta distribution has a few properties, such as finite positive intercepts in the x-axis and adjustable skewness, that make it highly desirable as a distribution for age in a manpower planning model. In this paper we have developed an approach for dynamically computing the retirement probability, and hence the retirement rate, when the age of manpower in a pool follows beta-distribution. We have made a comparative evaluation of the two distributions in the framework of a simple manpower planning system dynamics model, and we have shown that various manpower-related variables assume more reasonable values for the beta-distributed age compared to the normal-distributed age. Thereafter we have applied the approach to a two-stage hierarchical manpower planning model in an R & D laboratory and have studied the behavior of the manpower-related variables under two recruitment policies. We have demonstrated in this paper that assuming beta-distributed age presents no difficulty while modelling for time-scale promotion, a combination of time-scale and merit promotion, and recruitment of persons at different age groups.
Shivanagaraju, C., Mahanty, B., Vizayakumar, K., & Mohapatra, P. K. J. (1998). Beta-distributed age in manpower planning models. Applied Mathematical Modelling, 22(1–2), 23–37. https://doi.org/10.1016/S0307-904X(98)00006-7