Multiple activity chart:
It is a chart where activities of more than subject (worker or equipment) are recorded on a common time scale to show their inter-relationship. Multiple activity chart is made to
• Study idle time of the man and machines.
• Determine number of machines handled by one operator
• Determine number of operators required in teamwork to perform the given job. Construction of the chart:
A Multiple activity chart consists of a series of bars (columns) placed against a common time scale. Each subject is allocated one bar and the activities related to the subjects are represented in this bar. The columns are placed against a common time scale which starts at zero and ends at cycle time of the job. The task to be recorded is broken into smaller elements and time for each element is measured with the help of a stop watch. The activities are then recorded in the chart in their respective columns.
Two symbols are used in the chart – One representing working and other idle. Working is represented by hatched column and idle id represented by blank as shown in fig.
Multiple activity chart is extremely useful in organizing teams of operatives on mass production work. This is also used in maintenance. It is used to determine the number of machines which is operator can handle. It is useful in:
• Reducing idle time of machines and operators.
• Combine or eliminate some of the operations.
• It helps to explore ways to increase utilization of men and machines.