Available-to-promise (ATP) is the uncommitted portion of a company’s inventory and planned production maintained in the master schedule to support customer-order promising. ATP is calculated by subtracting the customer orders and forecast from the projected on-hand inventory. The projected on-hand inventory is calculated by adding the beginning inventory and the master production schedule (MPS) and subtracting the customer orders.The largest customer order that could be accepted for delivery at the end of week 3 without making changes to the MPS is the ATP at the end of week 3. To calculate the ATP, we need to fill in the projected on-hand inventory for each week using the given information:

Table

Week

Forecast

Customer Orders

MPS

Projected On-Hand Inventory

ATP

1

20

22

0

43 + 0 - 22 = 21

21 - 20 = 1

2

20

17

0

21 + 0 - 17 = 4

4 - 20 = -16

3

20

10

80

4 + 80 - 10 = 74

74 - 20 = 54

The ATP at the end of week 3 is 54, which means that the company can promise 54 units of inventory to customers without changing the MPS. However, the question asks for the largest customer order that could be accepted, which means that we need to consider the existing customer orders as well. The customer orders for week 3 are 10, which means that the company has already committed 10 units of inventory to customers. Therefore, the largest customer order that could be accepted for delivery at the end of week 3 is 54 + 10 = 64 units. However, this is not one of the options given in the question. The closest option that is less than or equal to 64 is 61, which is option C12 References: 1: CPIM Part 1 - Section A - Module 1 - Session 4 - Master Scheduling 2: CPIM Part 1 - Section A - Module 1 - Session 5 - Available to Promise