Operations Management 101: Capacity Management - Economies and Diseconomies of Scale

What This Is

Economies and diseconomies of scale refer to the relationship between the size of an organization and its costs, efficiency, and productivity. As an organization grows, it may experience economies of scale, where costs decrease per unit due to increased production volume, but eventually, it may reach a point where diseconomies of scale set in, and costs increase due to inefficiencies and complexity. Understanding these concepts is crucial in operations management as it helps organizations make informed decisions about production planning, capacity allocation, and resource utilization. For example, Toyota's efficient production system allows it to produce high-quality vehicles at a lower cost per unit, giving it a competitive advantage in the market.

Key Formulas & Frameworks

• Economies of Scale (EOS): The cost savings achieved by increasing production volume, resulting in lower costs per unit. EOS can be calculated using the formula: EOS = (Total Cost / Total Units) - (Variable Cost / Units)
• Diseconomies of Scale (DOS): The increased costs and inefficiencies that occur as an organization grows beyond a certain point. DOS can be caused by factors such as bureaucracy, communication breakdowns, and resource misallocation.
• Break-Even Point (BEP): The point at which an organization's total revenue equals its total fixed and variable costs. BEP can be calculated using the formula: BEP = (Fixed Costs / (Selling Price - Variable Cost))
• Optimal Batch Size (OBS): The batch size that minimizes the total cost of production, including setup costs and holding costs. OBS can be calculated using the formula: OBS = ?(2DS/H) where D = annual demand, S = ordering cost, and H = holding cost per unit per year.
• Little's Law: A framework for understanding the relationship between inventory, throughput, and cycle time. WIP = Throughput × Cycle Time
• Productivity: A measure of efficiency, calculated as the ratio of output to input. Productivity = Output / Input
• Efficiency: A measure of how effectively resources are used, calculated as the ratio of actual output to effective capacity. Efficiency = Actual Output / Effective Capacity
• Utilization: A measure of how much of an organization's capacity is being used, calculated as the ratio of actual output to design capacity. Utilization = Actual Output / Design Capacity

Step-by-Step Application

1. Calculate the break-even point: Determine the fixed and variable costs, selling price, and demand to calculate the break-even point.
2. Determine the optimal batch size: Calculate the optimal batch size using the OBS formula, considering the ordering cost, holding cost, and annual demand.
3. Analyze economies and diseconomies of scale: Evaluate the organization's production volume and costs to determine if economies or diseconomies of scale are present.
4. Optimize production planning: Use Little's Law to understand the relationship between inventory, throughput, and cycle time, and adjust production planning accordingly.
5. Monitor productivity and efficiency: Track productivity and efficiency metrics to identify areas for improvement and optimize resource utilization.

Common Mistakes

• Mistake: Confusing efficiency with utilization.
• Correction: Efficiency measures how effectively resources are used, while utilization measures how much of an organization's capacity is being used. Don't confuse them.
• Mistake: Not considering the impact of diseconomies of scale on production planning.
• Correction: As an organization grows, diseconomies of scale can lead to increased costs and inefficiencies. Consider these factors when making production planning decisions.
• Mistake: Not calculating the optimal batch size.
• Correction: Failing to calculate the optimal batch size can lead to suboptimal production planning and increased costs.

Exam / Certification Tips

• Tricky distinction: Between efficiency and utilization. Make sure to understand the difference between these two metrics.
• APICS terminology: Familiarize yourself with APICS terminology, such as "push vs pull" and "planned vs actual capacity."
• Six Sigma terminology: Understand the difference between Cp and Cpk, and how they relate to process capability.
• Common question patterns: Expect questions that require you to apply the concepts of economies and diseconomies of scale to real-world scenarios.

Quick Practice Problem

Scenario: A manufacturing company produces 100 units per day with a production rate of 120 units per hour. What is the takt time?

Answer: 1 hour Explanation: Takt time is the time available to produce one unit, calculated as 1 / (production rate - demand rate). In this case, the takt time is 1 hour.

Last-Minute Cram Sheet

• EOS = (Total Cost / Total Units) - (Variable Cost / Units)
• DOS: Increased costs and inefficiencies that occur as an organization grows beyond a certain point.
• BEP = (Fixed Costs / (Selling Price - Variable Cost))
• OBS = ?(2DS/H)
• WIP = Throughput × Cycle Time
• Productivity = Output / Input
• Efficiency = Actual Output / Effective Capacity
• Utilization = Actual Output / Design Capacity
• "Efficiency" is actual output / effective capacity; "Utilization" is actual output / design capacity – don't confuse them
• Diseconomies of scale can lead to increased costs and inefficiencies – consider these factors in production planning