Establish Standardized Processes and Procedures 129
Chapter 6. Establish Standardized Processes and Procedures 129
likely be the waste of waiting by the operator. The operator may perform mis- cellaneous tasks to “keep busy,” such as getting the next parts ready or “organ- izing” the work area (we observed one operator neatly restacking every part in the bin, which looked nice but was of no value). It is not clear what the cycle time of the robot is. The Standardized Work Combination Table (Figure 6-6) is useful for this situation.
Figure 6-6 shows the same job depicted on a Standardized Work Combination Table. Read it by following the work elements one by one from left to right, and you can see where in the cycle the operator walks to perform the next work element. In this example the operator picks up Bracket A in one second, walks to the machine in two seconds, loads Bracket A in six seconds, walks to get the next part in two seconds, and so on. By Step 11 all of the parts are loaded into the robotic welder, and you see by the dotted line that the machine cycles for 23 seconds.
Takt Time Manual Part Name
Process Name
Date:
Standardized Work
Automatic Part#
Combination Table
Group:
Walking 76
Operation Time (Seconds) #
Time Elements
10 20 30 40 50 60 70 1 Pick up Bracket A
Work Elements
1 2 Wait Time 2 Load in fixture
3 Pick up Bracket B
4 Load in fixture
5 Pick up Side Support
6 Load in fixture
7 Pick up Stiffener
8 Load in fixture
9 Pick up Brace
10 Load in fixture
11 Start Robot cycle
Figure 6-6. Standardized Work Combination Table with one robot
T HE T OYOTA W AY F IELDBOOK
This is a fairly simple job in terms of the operator-machine interface. More complex jobs may have an operator who moves within a cell and operates three or four machines. Like the Standardized Work Chart, the Standardized Work Combination Table converts the work into a visual format so the work/walk/wait time relationships can clearly be seen (the waiting time on this job should be the first improvement target!). The waiting time occurs after the operator starts the robot cycle. This time should be utilized for additional value-adding activity.
Figure 6-7, below, shows the same job with the addition of a secondary task by adding loading and unloading of a second automatic operation. Notice that the operation time “wraps around,” meaning the machine operates beyond the takt time relative to the start time of the operation. The important thing to note is that the second robot completes its cycle before the operator is ready to return to reload it (the robots have an automatic unload feature, which is common in
Takt Time Manual Part Name
Process Name
Date:
Standardized Work
Automatic Part #
Combination Table
Group:
Walking 76
Operation Time (Seconds) #
Time Elements
10 20 30 40 50 60 70 1 Pick up Bracket A
Work Elements
2 Load in fixture
3 Pick up Bracket B
4 Load in fixture
5 Pick up Side Support
6 Load in fixture
7 Pick up Stiffener
8 Load in fixture
9 Pick up Brace
10 Load in fixture
11 Start Robot cycle
Pick up battery tray and 12 Bracket