Stan’s Furniture Refinishers has 7 items of furniture to sand first and then varnish using the sending and varnishing machines, respectively. The items and their times on these two machines are shown in the table:

Item Sanding time, hrs. Varnishing time, hrs.
A 8 7
B 6 4
C 5 8
D 8 12
E 10 14
F 12 8
G 4 6

Questions.

Using the Johnson’s rule, identify the optimal sequencing of these jobs. The jobs must go through the machines in the same order starting with the sanding machine.

Identify the cumulative flow time for the initial sequencing and for the sequencing based on the Johnson’s rule. Provide the existing sequence chart and Johnson’s rule charts.