解題
### **Part (a): Overhead Analysis Sheet**
| Overhead Cost | Basis of Apportionment | Machining ($) | Assembly ($) | Finishing ($) | Maintenance ($) | Canteen ($) | Total ($) |
| :--- | :--- | :---: | :---: | :---: | :---: | :---: | :---: |
| Indirect Materials | Direct Allocation | 12,000 | 8,000 | 6,000 | 4,000 | 2,000 | 32,000 |
| Indirect Labor | Direct Allocation | 18,000 | 22,000 | 14,000 | 8,000 | 5,000 | 67,000 |
| Rent and Rates | Floor Area (4:3:2:0.6:0.4) | 36,000 | 27,000 | 18,000 | 5,400 | 3,600 | 90,000 |
| Power | Kilowatt Hours (8:4:2:1:0) | 24,000 | 12,000 | 6,000 | 3,000 | 0 | 45,000 |
| Depreciation | NBV of Machinery (12:4:2:2:0) | 36,000 | 12,000 | 6,000 | 6,000 | 0 | 60,000 |
| **Total Allocated/Apportioned** | | **126,000** | **81,000** | **50,000** | **26,400** | **10,600** | **294,000** |
*Workings:*
* **Rent and Rates ($90,000):** Allocated based on Floor Area (total 10,000 sq m)
* Machining: \( 90,000 \times \frac{4,000}{10,000} = \$36,000 \)
* Assembly: \( 90,000 \times \frac{3,000}{10,000} = \$27,000 \)
* Finishing: \( 90,000 \times \frac{2,000}{10,000} = \$18,000 \)
* Maintenance: \( 90,000 \times \frac{600}{10,000} = \$5,400 \)
* Canteen: \( 90,000 \times \frac{400}{10,000} = \$3,600 \)
* **Power ($45,000):** Allocated based on Kilowatt Hours (total 15,000 kWh)
* Machining: \( 45,000 \times \frac{8,000}{15,000} = \$24,000 \)
* Assembly: \( 45,000 \times \frac{4,000}{15,000} = \$12,000 \)
* Finishing: \( 45,000 \times \frac{2,000}{15,000} = \$6,000 \)
* Maintenance: \( 45,000 \times \frac{1,000}{15,000} = \$3,000 \)
* Canteen: \( 45,000 \times 0 = \$0 \)
* **Depreciation ($60,000):** Allocated based on Net Book Value of Machinery (total $200,000)
* Machining: \( 60,000 \times \frac{120,000}{200,000} = \$36,000 \)
* Assembly: \( 60,000 \times \frac{40,000}{200,000} = \$12,000 \)
* Finishing: \( 60,000 \times \frac{20,000}{200,000} = \$6,000 \)
* Maintenance: \( 60,000 \times \frac{20,000}{200,000} = \$6,000 \)
* Canteen: \( 60,000 \times 0 = \$0 \)
---
### **Part (b): Re-apportionment of Service Department Overheads (Step-Down Method)**
1. **Maintenance Department (Total = $26,400)**
* Apportioned based on Maintenance Hours Worked: Machining (1,200), Assembly (600), Finishing (400), Canteen (200). Total hours = 2,400.
* Rate: \( \frac{\$26,400}{2,400 \text{ hours}} = \$11.00 \text{ per hour} \)
* Machining: \( 1,200 \times \$11 = \$13,200 \)
* Assembly: \( 600 \times \$11 = \$6,600 \)
* Finishing: \( 400 \times \$11 = \$4,400 \)
* Canteen: \( 200 \times \$11 = \$2,200 \)
2. **Canteen Department (Total = $10,600 (original) + $2,200 (re-apportioned) = $12,800)**
* Apportioned based on Number of Employees in Production Departments only: Machining (18), Assembly (14), Finishing (8). Total employees = 40.
* Machining: \( \$12,800 \times \frac{18}{40} = \$5,760 \)
* Assembly: \( \$12,800 \times \frac{14}{40} = \$4,480 \)
* Finishing: \( \$12,800 \times \frac{8}{40} = \$2,560 \)
**Summary of Re-apportionment:**
| Department | Machining ($) | Assembly ($) | Finishing ($) | Maintenance ($) | Canteen ($) |
| :--- | :---: | :---: | :---: | :---: | :---: |
| Initial Totals | 126,000 | 81,000 | 50,000 | 26,400 | 10,600 |
| Re-apportion Maintenance | 13,200 | 6,600 | 4,400 | (26,400) | 2,200 |
| Re-apportion Canteen | 5,760 | 4,480 | 2,560 | — | (12,800) |
| **Total Overheads** | **144,960** | **92,080** | **56,960** | **0** | **0** |
---
### **Part (c): Overhead Absorption Rates (OAR)**
* **Machining:** Mainly capital-intensive (machine hours exceed labor hours). Appropriate base: **Machine Hours**.
* \( \text{OAR} = \frac{\$144,960}{12,080 \text{ machine hours}} = \$12.00 \text{ per machine hour} \)
* **Assembly:** Mainly labor-intensive (labor hours exceed machine hours). Appropriate base: **Direct Labor Hours**.
* \( \text{OAR} = \frac{\$92,080}{11,510 \text{ labor hours}} = \$8.00 \text{ per direct labor hour} \)
* **Finishing:** Mainly labor-intensive (labor hours exceed machine hours). Appropriate base: **Direct Labor Hours**.
* \( \text{OAR} = \frac{\$56,960}{14,240 \text{ labor hours}} = \$4.00 \text{ per direct labor hour} \)
---
### **Part (d): Selling Price for Job 412**
* **Direct Materials:** $450.00
* **Direct Labor:**
* Machining: \( 5 \text{ hours} \times \$15 = \$75.00 \)
* Assembly: \( 12 \text{ hours} \times \$12 = \$144.00 \)
* Finishing: \( 8 \text{ hours} \times \$10 = \$80.00 \)
* *Total Direct Labor:* $299.00
* **Prime Cost:** \( \$450.00 + \$299.00 = \$749.00 \)
* **Overheads Absorbed:**
* Machining: \( 15 \text{ machine hours} \times \$12.00 = \$180.00 \) (using Machining OAR based on machine hours)
* Assembly: \( 12 \text{ direct labor hours} \times \$8.00 = \$96.00 \) (using Assembly OAR based on labor hours)
* Finishing: \( 8 \text{ direct labor hours} \times \$4.00 = \$32.00 \) (using Finishing OAR based on labor hours)
* *Total Overheads:* $308.00
* **Total Cost:** \( \$749.00 + \$308.00 = \$1,057.00 \)
* **Add: Profit Markup (25% on cost):** \( \$1,057.00 \times 25\% = \$264.25 \)
* **Quoted Selling Price:** \( \$1,057.00 + \$264.25 = \$1,321.25 \)
---
### **Part (e): Evaluation of Absorption Costing for Pricing Decisions**
* **Advantage (Max 2 marks):**
* It ensures that all production costs (both fixed and variable) are fully recovered in the selling price, protecting the company from selling at an overall loss in the long run (1) + expansion/explanation (1).
* **Disadvantage (Max 2 marks):**
* Since fixed costs are allocated on an arbitrary basis, the resulting product cost can be inaccurate, which may lead to uncompetitive pricing or overpricing, causing loss of sales to competitors (1) + expansion/explanation (1).
* Alternatively, it is not suitable for short-term decision making (like accepting special one-off orders) where only marginal (incremental) costs are relevant (1).