Because the installation of machinery of any kind involves an initial outlay of money, it long ago became apparent to everybody that the “trial and error” method of buying machines or other commodities was wasteful and ruinous. It was not until recent years, however, that the closer study of operating costs disclosed the fact that the expense of “labour turnover,” that is to say the proportion of employees in any given business whose places have to be filled annually, is one of the heaviest avoidable drains on income. This was long overlooked because no capital investment is involved in the initial employment of labour. The cost of training new employees is much larger, it is now learned, in most businesses, than is generally understood, not only in the direct outlay in salary or wages before the new employee has mastered the duties of the new position as well as he or she is able, but in loss through spoiled materials, reduced individual output, and often in the slowing down of an entire chain of manufacturing operations through the inability of the inexperienced worker to maintain the pace of the rest of the links in the chain. If, then, as so often happens, it is found after experiment that the new employee is not capable of performing the work efficiently, the whole process must be repeated. The employee who has failed leaves, is dismissed, or is transferred to another department, and a new and equally inexperienced worker employed to fill the vacancy, with the whole cost of training to be incurred over again. Even though the new worker may be experienced in the particular class of work to be done, there is an appreciable loss due to the unavoidable frictions and hesitations that occur whenever a worker is being fitted into a new environment.