ECMM112 – Manufacturing Supply Chain Management

Ref/Def: Individual Assignment

Weight: 40% of total module marks
Structure: The assignment consists of three problems

Problem 1: Sales Forecasting [35 Marks]

Ms. Sarah Kim’s company manufactures and sells electric scooters. Monthly unit sales for a 10-month period are provided below:

Table 1: Monthly Sales Data

Tasks:

1. Plot the monthly sales data. (4 marks)
2. Compute the sales forecast for November using:
   • Four-month moving average (5 marks)
   • Weighted four-month moving average with weights Oct:0.4, Sep:0.3, Aug:0.2, Jul:0.1 (5 marks)
   • Linear trend projection (5 marks)
   • Exponential smoothing with α = 0.6, assuming initial forecast for February = 15,000 units (5 marks)
3. Evaluate which forecasting method appears most accurate, justifying your answer (5 marks)
4. Calculate the Mean Absolute Deviation (MAD) for each method and identify the method with lowest MAD (6 marks)

Problem 2: Regression Analysis [25 Marks]

Mr. David’s company produces and sells air purifiers. He wants to understand the relationship between advertising expenses and monthly sales. Data for the past 10 months is provided below:

Table 2: Advertising Expenses and Sales

Tasks:

1. Plot a scatter plot with advertising expenses on the x-axis and sales on the y-axis (5 marks)
2. Calculate the linear regression equation for this data (10 marks)
3. Using the regression equation, forecast sales for $11,000 advertising expenses (5 marks)
4. Determine the coefficient of determination (R²) and interpret its meaning in this context (5 marks)

Problem 3: Aggregate Planning [40 Marks]

Greentech Industries manufactures solar panels and needs an aggregate plan for the next six months.

Table 3: Costs

Table 4: Demand Forecast

Other Data:

• Current workforce (October): 15 workers
• Labor hours per unit: 2 hours
• Workdays per month: 20
• Beginning inventory: 300 units
• Ending inventory requirement: 0 units

Tasks:

1. Calculate the cost of a strategy where the workforce is varied to meet production demands each month, starting with 15 workers (15 marks)
2. Calculate the cost of a strategy with a constant workforce of 15 workers, using overtime and inventory to meet demand (15 marks)
3. Provide recommendations to Greentech Industries to minimize costs while meeting demand. Justify your suggestions (10 marks)