Prepare a flow process chart for precutting the chords of the roof truss using a single table-mounted power saw. Notice that two cuts at different angles (a vertical or plumb cut at one end and an angle cut at the other end) must be made on each chord. Two chords are required per truss. The steps in the process to be charted are as follows:
A piece of raw material is removed from the storage pile, carried to the saw, and positioned on the saw table, one cut is made, and the partially precut piece is removed and placed in a temporary storage pile. After the pieces have all been cut, the saw is reset for the second cut angle, and the process is repeated for the second cut. However, after the second cut the piece is placed into a precut storage pile for use in truss assembly. Use the following job planning data in preparing your flow process chart. The subject to be charted is material.
Hand transport rate, loaded = 2.5 ft/s (0.76 m/s)
Hand transport rate, unloaded = 4.5 ft/s (1.37 m/s)
Job efficiency = 50 min/h
Make saw cut = 2 s
Position piece at saw = 2 s
Power saw to precut storage = 25 ft (7.6 m)
Power saw to temporary storage = 15 ft (4.6 m)
Raw material stack to saw = 15 ft (4.6 m)
Remove cut piece from saw = 3 s
Remove material from stack = 3 s
Stack material = 3 s