92 Some Aspects of Manpower Planning Models
ACTUARIAL SOME MODELS ASPECTS FOR OF STAFFS
NOTE PLANNING AN ORDERED
HIERARCHY by W. V. WEBB, F.F.A.
[Originally presented by the author at a N.A.T.O. conference and printed in Manpower Planning Models published by The English Universities Press Ltd] 1. Introduction A manpower planning model might be described as a device which looks into the future to provide guidelines for present action. This paper examines mainly the situation which would arise if stable conditions of recruitment, wastage, retirement, and the numbers in each grade within the hierarchy persisted for many years. Such an ideal is unlikely ever to be realised in practice, but the resulting model, sometimes called a “ steady-state ” model, is very useful as a standard from which to measure departures from the ideal, and to give early warning of future problems that may be inherent in present age and grade distributions. 2. Elements incorporated in the model (a) Grades of stuff. Suppose that the staff employed in a certain part of an organisation are classified in four grades, and that the number of posts in each grade that are required for the proper functioning of the organisation are known. (b) Recruitment. Recruitment is to the lowest grade only, but can take place over a wide age-range, and includes recruits from different sources and of different quality. (c) Promotion. Promotion is made from grade to grade to fill the higher posts as they fall vacant. Selection depends on service, age, ability, and the needs of the organisation. (d) Retirement. There are assumed to be rules about retirement on grounds of age, which take into account length of service, continuing efficiency, needs of the organisation, and wishes of the individual.
(e) Other wastage. Staff may leave through death, ill-health retirement, voluntary or involuntary resignation, or redundancy. 3. Data It is desirable to obtain sufficient information to enable an analysis to be made of the experience of the staff in respect of these elements over at least the last three years. Men and women will be dealt with separately and all analyses will be made by year of birth. Each year of experience will record for each grade the number of staff in post at the beginning and end of the year, the number of recruits, the number of promotions, the number of retirements and the number leaving through other causes. In addition, analyses of staff in post and promotions may be required according to year of recruitment. If the total numbers involved are large, trends in the experience can sometimes be observed during a period of three years. The basic data, and any such trends, must be adjusted for exceptional events such as an unusual volume of transfers or redundancies in a particular year or for known changes in future management policy. Apart from this, the average factors emerging from the experience are assumed to take account of the rules governing recruitment, promotion, wastage and retirement. Although qualitative considerations may be of primary concern in recruitment and promotion, they are often difficult to quantify and would greatly complicate the model by adding more dimensions to it. Provided that conditions have been reasonably stable, the average factors can be dealt with as functions solely of age, sex, and category of recruit. 4. Service table (Appendix A) The basic tool used in the calculations is the service table, akin to a life table but limited to the maximum working lifetime of staff within the organisation. Separate tables are required for each sex, but there is usually a strong correlation between age and grade making it unnecessary to have separate tables for each grade. Rates of wastage and retirement may therefore be calculated from the data for all grades combined. A simple method is to calculate the mean strength at...