Parts P1 - P7 are machined first on a milling machine and then polished at a separate machine. Using the information in the following table, the minimum total completion time required for carrying out both the operations for all 7 parts is _______ hours.

Part	Milling (hours)	Polishing (hours)
P1	8	6
P2	3	2
P3	3	4
P4	4	6
P5	5	7
P6	6	4
P7	2	1

Following data refers to the jobs $$(P, Q, R, S)$$ which have arrived at a machine for scheduling. The shortest possible average flow time is ___________ days.

Four jobs are to be processed on a machine as per data listed in the table.

If the Earliest Due Date $$(EDD)$$ rule is used to sequence the jobs, the number of jobs delayed is

Four jobs are to be processed on a machine as per data listed in the table.

Using the Shortest Processing Time $$(SPT)$$ rule, total tardiness is