Concept explainers
Using the data for the coffee table in Problem 14.31, build a labor
To determine: The number of labor hours and employees needed each day.
Explanation of Solution
Given information:
- Table requires 1 top, 4 legs, 1/8 gallon of strain, 1/16 gallon of blue, 2 short braces, 2 long braces, and brass cap on the bottom of each leg.
- 100 gallons of glue as inventory.
- All items except brass caps, stain and glue are planned on a Lot for lot basis.
- Caps are purchased in 1000’s, stain and glue by gallon.
- Lead time = 1 (for each item).
- 640 coffee tables needed on day 5 and 6.
- 128 coffee tables needed on days 7 and 8.
- Labor standard for each top is 2 labor hours.
- Each leg with brass cap installation and each pair of braces need ¼ hour.
- Base assembly needs 1 labor hour.
- Final assembly of table requires 2 labor hours.
- Number of hours per day is 8.
Product structure:
Net requirements plan:
Table:
Period (Day) | ||||||||
Table | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
Gross requirements | 640 | 640 | 128 | 128 | ||||
Scheduled receipt | ||||||||
On hand (0) | 0 | 0 | 0 | 0 | ||||
Net requirement | 640 | 640 | 128 | 128 | ||||
Planned order receipt | 640 | 640 | 128 | 128 | ||||
Planned order release | 640 | 640 | 128 | 128 |
Day 5:
The gross requirement is 640 (1 assembly) of Coffee table derived from the given information. The On hand is 0. Therefore, the net requirement is 640. The lead time is 1 week. The planned order release will be 640 in day 4 which will be the planned order receipt in day 5.
Day 6:
The gross requirement is 640 (1 assembly) of Coffee table derived from the given information. The On hand is 0. Therefore, the net requirement is 640. The lead time is 1 week. The planned order release will be 640 in day 5 which will be the planned order receipt in day 6.
Day 7:
The gross requirement is 128 (1 assembly) of Coffee table derived from the given information. The On hand is 0. Therefore, the net requirement is 128. The lead time is 1 week. The planned order release will be 128 in day 6 which will be the planned order receipt in day 7.
Day 8:
The gross requirement is 128 (1 assembly) of Coffee table derived from the given information. The On hand is 0. Therefore, the net requirement is 128. The lead time is 1 week. The planned order release will be 128 in day 7 which will be the planned order receipt in day 8.
Top:
Period (Day) | ||||||||
Top | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
Gross requirements | 640 | 640 | 128 | 128 | ||||
Scheduled receipt | ||||||||
On hand (0) | 0 | 0 | 0 | 0 | ||||
Net requirement | 640 | 640 | 128 | 128 | ||||
Planned order receipt | 640 | 640 | 128 | 128 | ||||
Planned order release | 640 | 640 | 128 | 128 |
Day 4:
The gross requirement is 640 (1 assembly) of Top derived from the planned order release of Table. The On hand is 0. Therefore, the net requirement is 640. The lead time is 1 week. The planned order release will be 640 in day 3 which will be the planned order receipt in day 4.
Day 5:
The gross requirement is 640 (1 assembly) of Top derived from the planned order release of Table. The On hand is 0. Therefore, the net requirement is 640. The lead time is 1 week. The planned order release will be 640 in day 4 which will be the planned order receipt in day 5.
Day 6:
The gross requirement is 128 (1 assembly) of Top derived from the planned order release of Table. The On hand is 0. Therefore, the net requirement is 128. The lead time is 1 week. The planned order release will be 128 in day 5 which will be the planned order receipt in day 6.
Day 7:
The gross requirement is 128 (1 assembly) of Top derived from the planned order release of Table. The On hand is 0. Therefore, the net requirement is 128. The lead time is 1 week. The planned order release will be 128 in day 6 which will be the planned order receipt in day 7.
Stain:
Period (Day) | ||||||||
Stain | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
Gross requirements | 80 | 80 | 16 | 16 | ||||
Scheduled receipt | ||||||||
On hand (0) | 0 | 0 | 0 | 0 | ||||
Net requirement | 80 | 80 | 16 | 16 | ||||
Planned order receipt | 80 | 80 | 16 | 16 | ||||
Planned order release | 80 | 80 | 16 | 16 |
Day 4:
The gross requirement is 80 (1 assembly) of Stain derived from the planned order release of Table. The On hand is 0. Therefore, the net requirement is 80. The lead time is 1 week. The planned order release will be 80 in day 3 which will be the planned order receipt in day 4.
Day 5:
The gross requirement is 80 (1 assembly) of Stain derived from the planned order release of Table. The On hand is 0. Therefore, the net requirement is 80. The lead time is 1 week. The planned order release will be 80 in day 4 which will be the planned order receipt in day 5.
Day 6:
The gross requirement is 16 (1 assembly) of Stain derived from the planned order release of Table. The On hand is 0. Therefore, the net requirement is 16. The lead time is 1 week. The planned order release will be 16 in day 5 which will be the planned order receipt in day 6.
Day 7:
The gross requirement is 16 (1 assembly) of Stain derived from the planned order release of Table. The On hand is 0. Therefore, the net requirement is 16. The lead time is 1 week. The planned order release will be 16 in day 6 which will be the planned order receipt in day 7.
Glue:
Period (Day) | ||||||||
Glue | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
Gross requirements | 40 | 40 | 8 | 8 | ||||
Scheduled receipt | ||||||||
On hand (100) | 100 | 60 | 20 | 12 | 4 | |||
Net requirement | 0 | 0 | 0 | 0 | ||||
Planned order receipt | ||||||||
Planned order release |
Day 4:
The gross requirement is 40 (1 assembly) of Glue derived from the planned order release of Table. The On hand is 100. Therefore, the net requirement is 0. Therefore there will be no planned order release. The excess inventory 60 will be available at week 5.
Day 5:
The gross requirement is 40 (1 assembly) of Glue derived from the planned order release of Table. The On hand is 60. Therefore, the net requirement is 0. Therefore there will be no planned order release. The excess inventory 20 will be available at week 6.
Day 6:
The gross requirement is 8 (1 assembly) of Glue derived from the planned order release of Table. The On hand is 20. Therefore, the net requirement is 0. Therefore there will be no planned order release. The excess inventory 12 will be available at week 7.
Day 7:
The gross requirement is 8 (1 assembly) of Glue derived from the planned order release of Table. The On hand is 12. Therefore, the net requirement is 0. Therefore there will be no planned order release. The excess inventory 8 will be available at week 8.
Base assembly:
Period (Day) | ||||||||
Base | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
Gross requirements | 640 | 640 | 128 | 128 | ||||
Scheduled receipt | ||||||||
On hand (0) | 0 | 0 | 0 | 0 | ||||
Net requirement | 640 | 640 | 128 | 128 | ||||
Planned order receipt | 640 | 640 | 128 | 128 | ||||
Planned order release | 640 | 640 | 128 | 128 |
Day 4:
The gross requirement is 640 (1 assembly) of base assembly derived from the planned order release of Table. The On hand is 0. Therefore, the net requirement is 640. The lead time is 1 week. The planned order release will be 640 in day 3 which will be the planned order receipt in day 4.
Day 5:
The gross requirement is 640 (1 assembly) of base assembly derived from the planned order release of Table. The On hand is 0. Therefore, the net requirement is 640. The lead time is 1 week. The planned order release will be 640 in day 4 which will be the planned order receipt in day 5.
Day 6:
The gross requirement is 128 (1 assembly) of base assembly derived from the planned order release of Table. The On hand is 0. Therefore, the net requirement is 128. The lead time is 1 week. The planned order release will be 128 in day 5 which will be the planned order receipt in day 6.
Day 7:
The gross requirement is 128 (1 assembly) of base assembly derived from the planned order release of Table. The On hand is 0. Therefore, the net requirement is 128. The lead time is 1 week. The planned order release will be 128 in day 6 which will be the planned order receipt in day 7.
Short brace:
Period (Day) | ||||||||
Short Brace | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
Gross requirements | 1,280 | 1,280 | 256 | 256 | ||||
Scheduled receipt | ||||||||
On hand (0) | 0 | 0 | 0 | 0 | ||||
Net requirement | 1,280 | 1,280 | 256 | 256 | ||||
Planned order receipt | 1,280 | 1,280 | 256 | 256 | ||||
Planned order release | 1,280 | 1,280 | 256 | 256 |
Day 3:
The gross requirement is 1,280 (2 assembly) of short brace derived from the planned order release of base assembly. The On hand is 0. Therefore, the net requirement is 1,280. The lead time is 1 week. The planned order release will be 1,280 in day 2 which will be the planned order receipt in day 3.
Day 4:
The gross requirement is 1,280 (2 assembly) of short brace derived from the planned order release of base assembly. The On hand is 0. Therefore, the net requirement is 1,280. The lead time is 1 week. The planned order release will be 1,280 in day 3 which will be the planned order receipt in day 4.
Day 5:
The gross requirement is 256 (2 assembly) of short brace derived from the planned order release of base assembly. The On hand is 0. Therefore, the net requirement is 256. The lead time is 1 week. The planned order release will be 256 in day 4 which will be the planned order receipt in day 5.
Day 6:
The gross requirement is 256 (2 assembly) of short brace derived from the planned order release of base assembly. The On hand is 0. Therefore, the net requirement is 256. The lead time is 1 week. The planned order release will be 256 in day 5 which will be the planned order receipt in day 6.
Long brace:
Period (Day) | ||||||||
Long Brace | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
Gross requirements | 1,280 | 1,280 | 256 | 256 | ||||
Scheduled receipt | ||||||||
On hand (0) | 0 | 0 | 0 | 0 | ||||
Net requirement | 1,280 | 1,280 | 256 | 256 | ||||
Planned order receipt | 1,280 | 1,280 | 256 | 256 | ||||
Planned order release | 1,280 | 1,280 | 256 | 256 |
Day 3:
The gross requirement is 1,280 (2 assembly) of long brace derived from the planned order release of base assembly. The On hand is 0. Therefore, the net requirement is 1,280. The lead time is 1 week. The planned order release will be 1,280 in day 2 which will be the planned order receipt in day 3.
Day 4:
The gross requirement is 1,280 (2 assembly) of long brace derived from the planned order release of base assembly. The On hand is 0. Therefore, the net requirement is 1,280. The lead time is 1 week. The planned order release will be 1,280 in day 3 which will be the planned order receipt in day 4.
Day 5:
The gross requirement is 256 (2 assembly) of long brace derived from the planned order release of base assembly. The On hand is 0. Therefore, the net requirement is 256. The lead time is 1 week. The planned order release will be 256 in day 4 which will be the planned order receipt in day 5.
Day 6:
The gross requirement is 256 (2 assembly) of long brace derived from the planned order release of base assembly. The On hand is 0. Therefore, the net requirement is 256. The lead time is 1 week. The planned order release will be 256 in day 5 which will be the planned order receipt in day 6.
Leg:
Period (Day) | ||||||||
Leg | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
Gross requirements | 2,560 | 2,560 | 512 | 512 | ||||
Scheduled receipt | ||||||||
On hand (0) | ||||||||
Net requirement | 2,560 | 2,560 | 512 | 512 | ||||
Planned order receipt | 2,560 | 2,560 | 512 | 512 | ||||
Planned order release | 2,560 | 2,560 | 512 | 512 |
Day 3:
The gross requirement is 2,560 (4 assembly) of leg derived from the planned order release of base assembly. The On hand is 0. Therefore, the net requirement is 2,560. The lead time is 1 week. The planned order release will be 2,560 in day 2 which will be the planned order receipt in day 3.
Day 4:
The gross requirement is 2,560 (4 assembly) of leg derived from the planned order release of base assembly. The On hand is 0. Therefore, the net requirement is 2,560. The lead time is 1 week. The planned order release will be 2,560 in day 3 which will be the planned order receipt in day 4.
Day 5:
The gross requirement is 512 (4 assembly) of leg derived from the planned order release of base assembly. The On hand is 0. Therefore, the net requirement is 512. The lead time is 1 week. The planned order release will be 512 in day 4 which will be the planned order receipt in day 5.
Day 6:
The gross requirement is 512 (4 assembly) of leg derived from the planned order release of base assembly. The On hand is 0. Therefore, the net requirement is 256. The lead time is 1 week. The planned order release will be 512 in day 5 which will be the planned order receipt in day 6.
Brass caps:
Period (Day) | ||||||||
Brass caps | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
Gross requirements | 2,560 | 2,560 | 512 | 512 | ||||
Scheduled receipt | ||||||||
On hand (0) | 0 | 440 | 880 | 368 | 856 | 856 | 856 | |
Net requirement | 2,560 | 2,120 | 0 | 144 | ||||
Planned order receipt | 3,000 | 3,000 | 1,000 | |||||
Planned order release | 3,000 | 3,000 | 1,000 |
Day 2:
The gross requirement is 2,560 (1 assembly) of brass caps derived from the planned order release of legs. The On hand is 0. Therefore, the net requirement is 2,560. The lead time is 1 week. The planned order release will be 3,000 (1 Lot = 1,000) in day 1 which will be the planned order receipt in day 2. The excess inventory of 440 is available at day 3.
Day 3:
The gross requirement is 2,560 (1 assembly) of brass caps derived from the planned order release of legs. The On hand is 440. Therefore, the net requirement is 2,120. The lead time is 1 week. The planned order release will be 3,000 (1 Lot = 1,000) in day 2 which will be the planned order receipt in day 3. The excess inventory of 880 is available at day 4.
Day 4:
The gross requirement is 512 (1 assembly) of brass caps derived from the planned order release of legs. The On hand is 880. Therefore, the net requirement is 0. Therefore, there will be no planned release. The excess inventory of 368 is available at day 5.
Day 5:
The gross requirement is 512 (1 assembly) of brass caps derived from the planned order release of legs. The On hand is 368. Therefore, the net requirement is 144. The lead time is 1 week. The planned order release will be 1,000 (1 Lot = 1,000) in day 4 which will be the planned order receipt in day 5. The excess inventory of 856 is available at the next day.
Calculation of labor hours / day:
Master Schedule | Hours Required | Day 1 | Day 2 | Day 3 | Day 4 | Day 5 | Day 6 | Day 7 | Day 8 |
Table assembly | 2 | 1280 | 1280 | 256 | 256 | ||||
Top preparation | 2 | 1280 | 1280 | 256 | 256 | ||||
Assemble base | 1 | 640 | 640 | 128 | 128 | ||||
Long brace (2) | 0.25 | 320 | 320 | 64 | 64 | ||||
Short brace (2) | 0.25 | 320 | 320 | 64 | 64 | ||||
Leg (4) | 0.25 | 640 | 640 | 128 | 128 | ||||
Total Hours | 0 | 1280 | 3200 | 3456 | 1920 | 640 | 256 | ||
Employees need @ 8 hours / day | 0 | 160 | 400 | 432 | 240 | 80 | 32 |
The master production schedule is derived from net requirements plan.
Formula to calculate number of hours / each day:
Formula to calculate the number of employees per 8 hour day:
Day 2:
Calculation of total hours for each day for each component:
Long brace:
Short brace:
Leg:
Calculation of total hours / day:
The total hours is calculated by summing all the hours needed for each component in a day.
Calculation of number of employees per 8 hour day:
The number of employees is calculated by dividing the total hours per day with the number of hours per day.
Day 3:
Calculation of total hours for each day for each component:
Top preparation:
Assemble base:
Long brace:
Short brace:
Leg:
Calculation of total hours / day:
The total hours is calculated by summing all the hours needed for each component in a day.
Calculation of number of employees per 8 hour day:
The number of employees is calculated by dividing the total hours per day with the number of hours per day.
Day 4:
Calculation of total hours for each day for each component:
Table assembly:
Top preparation:
Assemble base:
Long brace:
Short brace:
Leg:
Calculation of total hours / day:
The total hours is calculated by summing all the hours needed for each component in a day.
Calculation of number of employees per 8 hour day:
The number of employees is calculated by dividing the total hours per day with the number of hours per day.
Day 5:
Calculation of total hours for each day for each component:
Table assembly:
Top preparation:
Assemble base:
Long brace:
Short brace:
Leg:
Calculation of total hours / day:
The total hours is calculated by summing all the hours needed for each component in a day.
Calculation of number of employees per 8 hour day:
The number of employees is calculated by dividing the total hours per day with the number of hours per day.
Day 6:
Calculation of total hours for each day for each component:
Table assembly:
Top preparation:
Assemble base:
Calculation of total hours / day:
The total hours is calculated by summing all the hours needed for each component in a day.
Calculation of number of employees per 8 hour day:
The number of employees is calculated by dividing the total hours per day with the number of hours per day.
Day 7:
Calculation of total hours for each day for each component:
Table assembly:
Calculation of total hours / day:
The total hours is calculated by summing all the hours needed for each component in a day.
Calculation of number of employees per 8 hour day:
The number of employees is calculated by dividing the total hours per day with the number of hours per day.
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Chapter 14 Solutions
Principles Of Operations Management
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