Process Flow Analyzer

Methodology

What is Bottleneck Analysis?

Every linear production process has a bottleneck — the single step with the longest effective cycle time. This step limits the entire line's throughput, regardless of how fast the other steps are. Identifying and improving the bottleneck is the highest-leverage move in operations management.

Concept 1

Effective Cycle Time

The time it takes one step to process one unit, adjusted for the number of workers. More workers at a station reduce the effective time proportionally.

If a step takes 10 min with 1 worker, adding a 2nd worker reduces effective time to 5 min. Workers = 0 means a passive step (machine/cooling) — time is fixed.

Concept 2

The Bottleneck

The step with the longest effective cycle time. It determines the system's pace — you can only produce one unit per bottleneck cycle, no matter what. All other steps sit idle waiting.

With steps at 8m, 10m, 5m, 2m, 1m — the 10m step is the bottleneck. Maximum capacity = 60 ÷ 10 = 6 units/hour.

Concept 3

Pipeline Scheduling

Orders overlap in a pipeline: while order #2 is at step 1, order #1 is already at step 2. The Gantt chart shows this overlap. After the first delivery, new units come out at the bottleneck's pace.

First delivery = sum of all step times (throughput time). After that, one every cycle time. The pipeline is the reason factories are far faster than single-unit processing.

Why it matters

In a real factory, restaurant, or service line, identifying the bottleneck tells you exactly where to invest — adding workers, buying a second machine, or redesigning the step. Spending effort anywhere else has zero impact on throughput until the bottleneck is fixed. This is the core insight of the Theory of Constraints.

The pipeline visualization above shows orders flowing through the process. Notice how tokens queue before the bottleneck — this is what happens in practice: inventory builds up in front of the slowest step, while downstream steps wait idle.

Key formulas

Metric	Formula	What it means
Effective time	base_time ÷ max(workers, 1)	How long one step actually takes per unit, adjusted for parallel workers
Bottleneck	max(effective times)	The step with the longest effective time — it limits everything
Throughput time	Σ all effective times	Time for one unit to go from start to finish, end-to-end, no queue
Cycle time	= bottleneck time	Time between consecutive completed units at steady state
Capacity / hour	60 ÷ cycle time	Maximum units per hour at steady state
Utilization	step_time ÷ cycle_time × 100%	How busy each step is relative to the bottleneck pace

Pipeline scheduling rule

For any order i at step j, the start time follows a simple rule: it must wait for both the previous step of the same order, and the same step of the previous order. This creates the cascading Gantt pattern above.

start[i][j] = max( end[i][j-1], end[i-1][j] )
where end[i][j] = start[i][j] + effective_time[j]

Throughput time = end[0][last_step] — first unit, no pipeline benefit
Steady-state gap = bottleneck cycle time — after pipeline fills, one unit exits every CT minutes

How to use this tool

Adjust the time and crew sliders on the right to model your process. The animated pipeline shows orders flowing through your line in real time — watch how they queue before the bottleneck. The Gantt chart below shows the exact schedule for enough orders to fill a 60-minute window.

Try adding a second worker to the bottleneck step — you'll see the bottleneck shift to a different step, utilization patterns change, and capacity increase. This is the core exercise in process improvement: find the constraint, ease it, find the new constraint, repeat.