Capacity Planning and Production Management Essentials

Understanding Capacity and Performance

Restriction: Factors limiting system performance and restricting production output.

Capacity: The maximum number of units an installation can receive or produce within a given period to meet demand.

Capacity Planning Horizons

• Short-term: Less than one year.
• Medium-term: 1 to 5 years.
• Long-term: Greater than 5 years.

Types of Capacity

• Planned Capacity: The ideal maximum theoretical yield of the production system design.
• Effective Capacity: The operating limits a company expects to achieve based on staff and equipment availability.

Performance Metrics

Utilization Rate: The percentage of design capacity reached. Calculated as: (Actual Output / Design Capacity) × 100%.

Efficiency: The percentage of effective capacity utilized. Calculated as: (Actual Output / Effective Capacity) × 100%.

Capacity Decision Strategies

• Contraction: A last-resort strategy involving plant closings, layoffs, or technical stoppages.
• Expansion: Increasing capacity through infrastructure investment or additional resources.

Process Planning Steps

1. Calculate available capacity.
2. Determine future needs (capacity cushion).
3. Develop alternatives (contraction or expansion).
4. Assess alternatives using economic methods and decision trees.

Key Operational Concepts

Capacity Cushion: Maintaining extra inventory to ensure customer loyalty and meet demand fluctuations. Recommended value: 100% - Utilization Rate.

Bottleneck: A constraint in process capability (can be internal or external).

Measurement Approaches:

• Based on Production: Useful for processes with low inventory or small variations.
• Based on Input: Used for flexible, low-volume processes with stable production requirements.

Principles of OCD for Production Maximization

1. Balance the flow.
2. Maximizing resource efficiency is not the only way to fix a system.
3. Pay attention to hours lost within the system.
4. Maintain inventory in front of bottlenecks and assembly points.
5. Ensure system flow matches demand.
6. Activating a non-bottleneck resource is different from utilizing a bottleneck resource.
7. Evaluate all investments based on their impact on the entire system.

Scale Dynamics

Economies of Scale: The reduction in average unit cost as production rates increase, driven by fixed costs, construction, and material purchasing.

Diseconomies of Scale: The phenomenon where average cost per unit rises as plant size increases beyond an optimal point.