1. Method Name

Bottleneck Analysis

2. Alternative Names

Analysis of Constraints

3. Brief Description

A bottleneck is a point in a process that has the lowest capacity and thus limits the overall throughput of the entire system. Bottleneck analysis is the process of identifying, quantifying, and systematically resolving these points.

4. Purpose / When to Use

It is used whenever it is necessary to increase the overall performance, speed, or capacity of a process. Instead of making broad improvements, it focuses on the weakest link, because any improvement outside the bottleneck is simply a waste. It is a practical application of the principles of the Theory of Constraints (TOC).

5. Procedure / How to Apply It

1. Map the process: Create a process map (workflow map, VSM) and identify the individual steps.
2. Collect data: For each step, measure key metrics: cycle time, capacity (number of units per hour), and utilization rate.
3. Identify the bottleneck: A bottleneck is a step that has
: - The longest cycle time.
- The lowest capacity.
- The highest utilization rate (often close to 100%).
- Inventory piling up or work waiting ahead of it.
4. Analyze the causes: Determine why this step is a bottleneck (e.g., an outdated machine, a complex manual process, a shortage of staff).
5. Implement solutions: Apply the five steps of TOC. Focus on maximizing utilization and subsequently increasing the capacity of the bottleneck.

6. A Real-World Example

At a fast-food restaurant, an analysis revealed that the bottleneck was not food preparation but the cash register. During lunchtime, a long line formed in front of it (inventory backlog). Although the kitchen could prepare food in 2 minutes, the cashier took an average of 3 minutes to serve each customer. Solution: add a second cash register during the lunch rush or introduce self-service kiosks.

7. Benefits

- Targeted and effective improvement.
- Maximizing the return on investment in improvement.
- Improves workflow and reduces overall lead time.
- Easy to understand and visualize.

8. Risks / Limits

- Variable bottlenecks: In some systems, the bottleneck may vary depending on the product mix or other factors.
- Neglecting variability: Analysis often focuses on average values and may underestimate the impact of random fluctuations and failures.
- Incorrect identification leads to unnecessary investments.

9. Practical Tips

- Go to the Gemba: The best way to find a bottleneck is to go and observe the process firsthand and look for where work is piling up.
- A bottleneck isn’t always a machine: A bottleneck can also be a person (e.g., a single approver), a department, or even a company rule or policy.
- Distinguish between a bottleneck and a constraint: In TOC, a “constraint” is a broader concept that can also be political or market-related. A “bottleneck” is typically a physical capacity limitation in a process.