Bottleneck Analysis
Bottleneck analysis identifies the process step that limits the throughput of the entire system. The bottleneck determines maximum output -- improving anything else first is waste.
A bottleneck is the process step with the lowest capacity or longest cycle time in a chain. Like the narrowest point in a pipe, it determines the maximum flow of the entire system. No matter how fast other steps are, total output cannot exceed the bottleneck's capacity.
The Theory of Constraints (TOC) by Eliyahu Goldratt formalizes this: Identify the constraint, exploit it fully, subordinate everything else to it, elevate it (increase its capacity), and repeat. There is always exactly one active constraint in any system.
Bottlenecks are not always obvious. A machine running at 100% utilization looks productive, but if it cannot keep up with demand, it is starving the entire downstream process. Inventory piling up before a station is a classic bottleneck indicator.
Importantly, once a bottleneck is resolved, a new one emerges elsewhere. Bottleneck analysis is therefore not a one-time event but a continuous practice -- which aligns perfectly with the KATA improvement cycle.
Practical Example
A production line has 5 stations with cycle times of 45, 52, 68, 50, and 47 seconds. Station 3 (68 seconds) is the bottleneck. Even though all other stations could produce faster, the line output is limited to 68 seconds per part. Reducing station 3 to 55 seconds increases total throughput by 19%.
How Leanshift Helps
Leanshift measures cycle times across all process steps and automatically highlights the station with the longest time. This instant bottleneck identification saves hours of manual observation and analysis.
Frequently Asked Questions
How do you find the bottleneck?
Look for the station with the longest cycle time, the highest utilization, or the largest inventory queue in front of it. Measure cycle times at every station -- the data will reveal the constraint clearly.
Should you always fix the bottleneck first?
Yes. Improving a non-bottleneck step does not increase total output. Always focus improvement efforts on the current constraint -- it delivers the highest return on investment.
Can there be multiple bottlenecks?
Theoretically only one is the true constraint at any time. However, two stations can have nearly identical cycle times, making both near-bottlenecks. When you improve one, the other immediately becomes the constraint.
Related Terms
OEE (Overall Equipment Effectiveness)
OEE is the key metric for machine and equipment productivity. It combines availability, performance, and quality into a single percentage value.
Cycle Time
Cycle time measures how long a single process step actually takes -- from start to finished result. It is the foundation of every process analysis.
Throughput
Throughput is the rate at which a system produces finished output. It measures actual productive capacity and is limited by the bottleneck of the process.