Question

complete the mrp table for the "Button"

The table below shows the net weekly demand of Audi Car model. The lead time to receive the door is 2 weeks. In week 0, there are 5 cars and 15 doors in inventory. It is expected to receive 30 reworked doors in week 10

Week	8	9	10	11	12	13	14	15	16	17
Net demand (car)	20	25	40	12	5	32	24	18	16	30

Suppose that driver door has four buttons, and each other door has 1 electrical button for the window. It is expected to receive 80 buttons in week 10

Complete the following MRP table for the buttons:

Lead time for buttons is 1 week.

Week	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17
Gross Requirement
Net Requirement
Time-Phased Net Requirement
Planned Order Release

Answer 1

Answer:

Please refer the formulas to find the values in MRP Table

Formulas

Planned receipt = Time-phased net requirement

t = current week

t-1 = previous week

scheduled receipt = SR (if given)

On-hand inventory / projected ending inventory (t) = on-hand inventory (t-1) - gross requirement (t)

(if on-hand inventory (t-1) > gross requirement (t))

On-hand inventory / projected ending inventory (t) = 0 (if on-hand inventory (t-1) <= gross requirement (t))

Net requirement (t) = 0 (if, on-hand inventory (t-1) >= gross requirement (t))

Net requirement (t) = Gross requirement (t) – [on-hand inventory (t-1) + scheduled receipt] (if, on-hand inventory (t-1) + SR(t) < gross requirement (t))

Planned receipt (t) = Net requirement (t)

Planned order release = Planned receipt (t), but offsetted ahead by lead time (i.e. if Lead time 2, planned order release will be offsetted by 2 weeks)

NOTE: Here in this problem, how many driver doors are ordered and how many other doors are ordered is not mentioned. It should be given, since driver doors and other doors are not same.

Hence, I am forced to make two assumptions here.

1. A set of 4 doors require 7 buttons. (1 driver door- 4 buttons and 3 other doors - 3 buttons i.e. 7 buttons in total.). So, if quantity ordered for doors is a multiple of 4, like in period 9 to 12 (Planned order release) of MRP TABLE of doors. I directly divide the number by 4 and multiply by 7 to get the number of buttons. e.g. 48 doors is planned order release in period 9 of MRP Table door, that means (48/4)*7=84 buttons are gross requirement for Buttons. So, this is how gross requirement of buttons are calculated if the Planned order release of Mrp door is multiple of 4.
2. If the number of doors ordered is somewhat odd number i.e. not a multiple of 4. Like planned order release of period 8 (i.e. 130) in MRP Table of doors. Then I calculate, the multiple of 4 which is just lesser than 130. i.e.(32*4 = 128). So, 32 pairs of 4 doors will have 7 buttons. i.e. (32*7=224) .But, still 2 door's buttons are left to be bought (128 +2 = 130). Then,,out of 2 doors, I assume 1st door is driver door (with 4 buttons) and 2nd door is passenger door with 1 button. So, in total buttons are 224 + 4 + 1 =229 gross requirement of buttons in MRP Table week 8.

So, in a set of 4 doors, I always assume, 1st door as driver door (with 4 buttons) and rest three doors, I assume to have 1 button.

BOM

Please refer the MRP Table given below.

And Lead time for fixing doors to Car is also considered to be 0. Since, it doesn't take much time to add doors on car. Hence, LT in Audi car MRP Table is taken 0.

MRP Table of Audi Car

Since, LT = 0. Planned order release = Planned receipt. (No offsetting)

MRP Table of door

The gross requirement for doors is calculated by multiplying Planned order release of Audi Car MRP Table by 4.

Gross req. of week 8 for doors = 15 x 4 =60 and for week 9 = 25 x 4 =100 and similarly calculate for all.

Rest calculate using formula.

MRP Table for buttons

Gross req. for week 6 = (44/4)*7 + 1 (i.e. driver door with 4 buttons) = 77 + 4 = 81 buttons (Use assumption 2)

Gross req. for week 7 = 100/4 * 7 = 175 buttons

Gross req. for week 8. caclulated in assumption 2.

Rest gross req. calculate similarly.

Use above formulas to calculate other values