The two-handed process chart for Motion Study
The two-handed process chart is a process chart in which the activities of a worker's hands (or limbs) are recorded in their relationship to one another
The two-handed process chart shows the two hands (and if the feet are involved, feet also) of the operative moving or static in relation to one another, usually in relation to a time scale.
The two-handed process chart is prepared for analysis of repetitive operations. At least, one complete cycle of the work is to be recorded. Recording of every movement of the hand is recorded.
Symbols and Meanings
O OPERATION Is used for the activities of grasp, position, use, release,
etc., of a tool, component or material.
=> TRANSPORT Is used to represent the movement of the hand (or limb) to
or from the work, a tool or material.
D DELAY is used to denote time during which the hand or limb being charted is idle (although the others may be in use).
▼ HOLD is used to represent the activity of holding the work, a tool or material — that is, when the hand being charted is holding something.
Preparing the chart requires observation and this enables the motion study specialist to gain
an intimate knowledge of the motions involved in the job. Each motion is subjected to questioning from ECRS perspective. From the questioning, improvements are developed. A brain storming group can be formed for the questioning of each motion. The group can be shown some successful motion study examples through videos or printed articles and reports. The ideas that are generated should be written down in chart form when they occur. Different ideas are compared. The best method is
generally that which requires the fewest movements.
The two-handed process chart can be applied to assembly as well as component making jobs. In the assembly of small parts with close fits, "positioning" should be shown as a separate movement
apart from the actual assembling movement. Attention gets focused on the different movements that way improvements in each movement can be thought of during simplifying activity.