TOC and Lean in electronics manufacturing · Case study
TOC at Apator Telemetria helped reduce the analysed batch’s process lead time from 42 to 18 hours. The organisation used TOC to identify where to focus, and Lean tools to organise flow, balance work and sustain the change.
How should these results be read? The comparisons of 42 versus 18 hours and 32 versus 8 hours concern the process presented in this case study for a batch of 1780 units. The sales volume growth shown later provides context for the organisation’s development; the source material does not attribute it exclusively to any single action or tool.
A 42-hour lead time and one dominant constraint
The radio module manufacturing process analysed had three main stages: surface-mount technology (SMT), through-hole technology (THT) and packing. SMT took approximately 7 hours, THT 32 hours and packing 3 hours. THT therefore accounted for most of the total 42-hour process.
At the same time, different models were launched at multiple workstations and in several cells. Each could follow a different route, increasing complexity, dispersing attention and making deviations harder to spot quickly. Local improvements offered no assurance that the performance of the entire process would improve.
The operational problem
Multiple models, different work sequences and several parallel flows made it difficult to identify where intervention would actually shorten order fulfilment.
The TOC question
What currently limits the throughput of the whole system, and how can the other operations be subordinated to that constraint instead of optimising each one separately?
TOC at Apator Telemetria: five focusing steps
The team followed the five steps of the Process of Ongoing Improvement (POOGI). It first identified the factor limiting throughput, then made the most of its available potential, subordinated the other processes to it and only then increased its capacity. Once one constraint was removed, the cycle started again.
This is particularly important in high-variety manufacturing: a bottleneck need not remain permanently attached to one machine. Its location can change with the product mix, staffing, skills and current workload. Read more about this logic in what is TOC — the Theory of Constraints and on the Goldratt Consulting website.
TOC identified where to act. Lean helped determine how
1Identifying the constraintTimes for entire stages and individual operations were measured to distinguish the real constraint on flow from local problems.
2From cells to linesModels began passing through successive operations in one visible sequence. This made flow easier to observe and enabled a quick response to deviations.
3Line balancing and standard workOne Piece Flow, Line Balancing and Standard Work helped align the way work was performed with the pace of the constraint and reduce fragmentation.
4Controlling flowThe presentation identified Kanban, SMED and Drum–Buffer–Rope logic as tools supporting flow control.
TOC + Lean: two complementary systems
TOC helped select the point of focus for the entire system. Lean supplied methods for organising work and eliminating waste precisely where improvement mattered to flow.
TOC: find the constraintIdentify which resource, stage or skill currently limits the throughput of the whole process.
Lean: improve the way work is doneOrganise flow, balance operations, establish a standard and reduce waste around the point of focus.
POOGI: start againOnce the constraint moves, return to diagnosis. Improvement is a cycle rather than a one-off project.
When the bottleneck starts to move
Once the basic flow was organised, ‘floating’ constraints became visible. Depending on the product model and the load on the seven THT lines, a different operation could become the weakest link. The constraint could also cease to be a technological issue and shift to people’s skills.
A changing product mixChanges operation times and the position of the bottleneck, so balancing a line just once is not enough.
Make-to-order productionChanges in the sales plan quickly translate into changing demand for staffing and specific skills.
Skills as a constraintIn the soldering example, planned skills development maintained the ability to work to a 14-second takt time.
A readiness bufferTrained backup staff and a repeatable process for preparing replacements reduced the risk of flow stopping.
Daily routines that protect focus
Redesigning the line alone was not enough. Sustaining the result required a shared goal, team involvement and the ability to reject issues that did not affect the current constraint. Focus was supported by the production manager’s daily routines: Gemba Walks, performance reviews, operational meetings, work on problems and a deliberate buffer for unplanned events.
- A shared goal: the throughput of the whole system rather than maximum utilisation of each workstation.
- Visible flow: one sequence of operations that makes deviations easier to spot quickly.
- Decision discipline: priority goes to actions that improve the performance of the constraint.
- Skills development: training covers quality of execution, the working method, takt time and confirmation of readiness.
Results of TOC at Apator Telemetria, supported by Lean tools
| Metric | Before | After | Change |
|---|---|---|---|
| Total process time | 42 h | 18 h | −57% |
| THT stage time | 32 h | 8 h | −75% |
| Analysed batch size | 1780 units | 1780 units | unchanged |
| Sales according to GA, 2020–2025 context | 687 798 units | 1 234 628 units | +79.5% |
The chart also shows the company’s sales volume growth between 2020 and 2025. The final row should not, however, be treated as the isolated effect of TOC alone or a single Lean tool: many factors influence a company’s performance.
- Cell production was replaced by a clearer linear flow.
- Deviations could be identified sooner and linked more easily to the performance of the entire process.
- THT stage time fell by three quarters for the batch analysed.
- The organisation developed a response method for situations where employees’ skills became the constraint.
‘TOC identifies where to act. Lean shows how to act.’ Combining focus on the constraint with flow, standard work and people’s involvement helped avoid randomly trying to improve everything at once.
TOC at Apator Telemetria: lessons for other manufacturers
- Measure the entire flow. The longest stage may consume most of the time even when other workstations appear well utilised locally.
- Choose the point of focus first. TOC limits the number of parallel initiatives and directs energy towards changes that improve system performance.
- Then select the tools. One Piece Flow, balancing, standard work, Kanban and SMED are more effective when they support a clearly defined constraint.
- Skills can be the constraint. Their availability can be as important as machine capacity.
- Sustain results through routines. Visible performance, Gemba Walks and daily work on deviations turn a project into a management system.
Frequently asked questions
What did TOC change at Apator Telemetria?
TOC focused the work on the constraint. Together with reorganised flow and Lean tools, it helped reduce the total process time for the analysed batch from 42 to 18 hours.
Why were TOC and Lean combined?
TOC answered the question of where to focus effort, while Lean supplied methods for changing the way work was done: one-piece flow, line balancing, standard work, Kanban and SMED.
Does a bottleneck always stay in the same place?
No. With many product variants, the constraint’s location can depend on the model, current workload, staffing and available skills. That is why the five TOC steps form a cycle of continuous improvement.
Is the 79.5% sales increase exclusively a result of TOC?
That cannot be concluded from the presentation alone. The chart shows the company’s development but does not specify how much of the growth resulted from TOC and Lean.
Would you like to combine TOC and Lean in your organisation?
We help identify the real constraint, organise flow and apply Lean tools where they will improve the performance of the whole system.
To explore the topic further, see also TOC training for manufacturing (in Polish) and the recap of Breaking Down Silos: Lean and TOC (in Polish).
Source and scope of this publication. This article is based on the case study ‘TOC vs Lean — do we have to choose?’, presented by Marcin Kościan, Production Manager at Apator Telemetria (profile in Polish), at ‘Breaking Down Silos: Lean and TOC’ (Polish event page), held on 24 September 2026 in Wałbrzych. Operational results and sales data come from the presentation. The figure for 2026 has been omitted because the presentation does not clearly identify it as a full-year result.
