The simplicity of L. Solomon's solution to the manpower problem discussed in the preceding article is due partly to the use of compound interest functions but mainly to the fact that transfers to semi-skilled status and thence to the skilled classification each occur at a single point, after two and five years respectively, from entry. When dealing with the corresponding problems of, say, office staffs who are recruited upon leaving school or university and may serve until age 60 or 65 the conditions are very different. Transfers from one category to another, in this case promotions from grade to grade, generally occur at varying rates over a range of ages. Further, the work cannot be simplified by the use of compound interest functions, the full service-table technique must be employed.