Man-Machine Chart: Machines being costly, it is desirable to run them efficiently and economically. The man-machine chart (Gantt Chart) is a useful device in this direction to identify and eliminate losses of capacity. Durations of elements of operation of man and machine recorded in their sequence, placed side by side and compared. The time of operations transports and waits occurring in the operators’ cycle and the time of start up, shut down, machining time and idle time in the machine cycle ruled off by proportionate symbol columns.
The length of symbol columns representing a wait period of man and machine are colored in red to distinguish it from their productive periods. Per piece machine operating’ time, machine idle time, man hours and man delay hours concluded. Application of the chart for group work estimated by first assuming the theoretical crew necessary to run the machine; at the required output and then trying to organize the same number of practical people to do the job.
A general rule to decide first what has to done and then how to fit people; to do the work and not vice versa followed. The standard times found by work measurement divided; by a correction factor 1.25 to consider levelling and compensating rest allowance. The charts prepared for the purpose ‘of analyzing the present method of performance of the operation and improving on it.