Learning Curve
1. **Problem Statement:**
Calculate average labour hours per unit for 1, 2, 4, and 8 units, total cumulative labour hours for 8 units, and total labour cost using an 80% learning curve with initial unit time 600 hours. Also explain factors causing deviations and managerial applications.
2. **Learning Curve Model:**
The average time per unit when cumulative output doubles is multiplied by the learning rate (80% or 0.8).
3. **Calculate average labour hours per unit:**
The formula for average time per unit at cumulative output $N$ is:
$$T_N = T_1 \times N^{\log_2 b}$$
where $T_1=600$ hours, $b=0.8$ (learning rate).
Calculate $\log_2 0.8$:
$$\log_2 0.8 = \frac{\ln 0.8}{\ln 2} \approx \frac{-0.2231}{0.6931} \approx -0.3219$$
Now calculate average times:
- For 1 unit:
$$T_1 = 600 \times 1^{-0.3219} = 600$$
- For 2 units:
$$T_2 = 600 \times 2^{-0.3219} = 600 \times 0.8 = 480$$
- For 4 units:
$$T_4 = 600 \times 4^{-0.3219} = 600 \times 0.8^2 = 600 \times 0.64 = 384$$
- For 8 units:
$$T_8 = 600 \times 8^{-0.3219} = 600 \times 0.8^3 = 600 \times 0.512 = 307.2$$
4. **Calculate total cumulative labour hours for 8 units:**
Total time is sum of times for each unit. Using the cumulative average time formula:
$$Y_N = T_1 \times \frac{N^{\log_2 b + 1}}{N} = T_1 \times N^{\log_2 b}$$
But more straightforward is to use the cumulative average time formula:
$$Y_N = T_1 \times N^{\log_2 b}$$
which is the average time per unit for $N$ units.
Total cumulative hours for $N$ units:
$$C_N = Y_N \times N = T_1 \times N^{\log_2 b} \times N = T_1 \times N^{1 + \log_2 b}$$
Calculate exponent:
$$1 + \log_2 0.8 = 1 - 0.3219 = 0.6781$$
Calculate total hours for 8 units:
$$C_8 = 600 \times 8^{0.6781}$$
Calculate $8^{0.6781}$:
$$8^{0.6781} = e^{0.6781 \times \ln 8} = e^{0.6781 \times 2.0794} = e^{1.409} \approx 4.09$$
So:
$$C_8 = 600 \times 4.09 = 2454$$ hours (approx)
5. **Calculate total labour cost:**
Labour cost per hour = 500
Total cost:
$$\text{Cost} = 2454 \times 500 = 1,227,000$$
6. **Factors causing deviations from theoretical learning curve:**
- Variability in worker skill levels and training.
- Changes in production methods or technology.
- Interruptions or delays in supply chain or equipment.
7. **Managerial applications of learning curve:**
- Cost estimation: Predict future labour costs as production increases.
- Budgeting: Plan budgets based on expected reductions in labour hours.
- Production planning: Schedule resources and timelines considering improved efficiency.