PTS Systems

PTS (Predetermined Time system) took a long time to become part of general work study practice. The main reason for this delay is probably the considerable number and variety of systems that have been produced, together with the fact that many of them would be obtained only by employing consultants. At present, over 200 such systems exist.

1) Any PTS system is rather complicated. It is not easy to learn and a work study man needs a good deal of practice before he can apply it correctly.
2) The task of learning enough about the various systems to be able to judge their claims and their relative merits is an almost impossible one. For example some systems do not go into sufficient detail in defining a certain motion.
3) PTS systems do not, as was claimed, eliminate the need for the stop watch, any more than they eliminate method study or work sampling.
4) Machine time, process time and waiting time are not measurable with PTS systems and occasional or incident elements are often more economically measured by using other techniques.
5) In fact it is difficult to obtain 100% coverage in a plant using only a PTS system and for certain operations such as batch production or non-repetitive jobs the use of such a system can be an expensive proposition.
6) It is invalid to add up times for individual small motions in the way required by PTS systems because the time taken to perform a particular motion is influenced by the motions preceding and following it.