Question

Children's scissors are made from four items: two identical blades, a 6-32 screw, and a nut. The blades are manufactured internally with a two-week lead time, and the screw and the nut are purchased from a hardware supplier each with a one-week lead time. The assembly process for one gross (which is equal to 12 dozen) of scissors takes one week. There is an order for one gross of scissors in week 7 and another for three in week 9. Moreover, there are 360 blades, 600 screws, and 100 nuts currently available in inventory.

(1) Construct a product structure tree for the scissors.

(2) Set up an MRP table for each of the four items comprising the scissors. It is assumed that the lot-for-lot rule is used to determine the planned order releases.

Answer 1

Answer 1:-

Answer 2:-

2. The MRP tables are as follows:

Level 0 – Scissors: lead time (LT) = 1 week

	1	2	3	4	5	6	7	8	9
Gross requirements							144		432
Scheduled receipts
Projected on-hand	0	0	0	0	0	0	-144		-432
Net requirements							144		432
Planned order receipts							144		432
planned order release						144		432

Level 1 – Blade: lead time (LT) = 2 weeks

	1	2	3	4	5	6	7	8	9
Gross requirements						288		864
Scheduled receipts
Projected on-hand	360	360	360	360	360	72	72	-792
Net requirements								792
Planned order receipts								792
planned order release						792

Level 1 – Screw: lead time (LT) = 1 week

	1	2	3	4	5	6	7	8	9
Gross requirements						144		432
Scheduled receipts
Projected on-hand	600	600	600	600	600	456	456	456	24
Net requirements
Planned order receipts
planned order release

Level 1 – Nut: lead time (LT) = 1 week

	1	2	3	4	5	6	7	8	9
Gross requirements						144		432
Scheduled receipts
Projected on-hand	100	100	100	100	100	-44		-432
Net requirements						44		432
Planned order receipts						44		432
Planned order release					44		432