Aluminium Extrusion Performance. How to Interpret Production Results

Product mix, batch size and the actual production sequence all influence extrusion performance.

Productivity expressed in kilograms per hour is one of the fundamental indicators in aluminium extrusion. It is measurable, easy to compare and directly connected with production capacity and manufacturing cost.

The same press can achieve very different kg/h results depending on what is being produced and how production is organised.

Profile characteristics, batch size, regular changeovers, die trials and interrupted production runs all affect the final result. kg/h should therefore remain a clear and consistent KPI, but its interpretation requires an understanding of the production behind it.

Product mix

A relatively heavy and straightforward profile and a lightweight profile with demanding geometry create very different production conditions.

Profile weight per metre, geometry, number of die cavities, achievable extrusion speed, cooling requirements and downstream handling all influence achievable output.

Productivity is therefore not a fixed characteristic of an extrusion press.

A week dominated by heavier and relatively straightforward profiles cannot be directly compared with one containing a significantly higher share of lightweight or technically demanding products without considering the difference in product mix.

There is no need to adjust the overall KPI every time the mix changes. kg/h should remain simple and comparable at plant level. At profile level, however, each product has defined technological parameters, and the objective is to achieve the most efficient and stable production possible within those parameters.

When the overall result moves significantly, one of the first questions should therefore be:

What were we actually producing?

Batch size

Production run length has a similar impact.

Every new run requires the process to reach stable production conditions. Depending on the profile and die, adjustments may be required before consistent production is achieved.

In a long production run, this initial phase represents a relatively small part of the total output. In a short run, the same phase is spread across a much smaller quantity of finished product, increasing its impact on both time and material efficiency.

Two dies running at a similar stable extrusion rate can therefore deliver different overall results if one remains in production for a long series while the other produces only a small batch.

Stable extrusion speed and overall order productivity are not the same thing.

Production starts are not all the same

The number of dies in a production plan does not necessarily describe the actual workload of the extrusion process.

A planned production sequence includes regular die changes. In practice, other types of starts also occur and should be distinguished when analysing performance.

One group consists of implementation trials. A new or modified die has to be tested and brought to the required production conditions. Such trials are part of introducing the die into production, but their effect on productivity and material consumption is different from established serial production.

Another group consists of interrupted runs on dies already in regular circulation. A die may have been successfully implemented and used in production, yet a particular run can still be interrupted and require correction or another start.

These events have different operational meanings.

Regular changeovers are part of the planned production structure. Implementation trials are part of bringing dies into serial production. An interruption on an established die means that a serial production run expected to be completed as planned was stopped before completion.

Putting all three into one number hides useful information.

Performance analysis should therefore distinguish between:

• regular production starts,
• implementation trials,
• and interrupted runs on dies already in regular circulation.

This gives a much clearer view of the actual production sequence than the number of planned dies alone.

Productivity and material yield

Productivity and scrap are normally reported as separate KPIs, but some of the factors affecting them are common.

Short batches and repeated starts increase the share of start-up conditions in total production. Implementation trials and interrupted runs can add further starts outside the original serial production sequence. The effect is visible not only in production time but also in material yield.

Product mix also matters. Profiles with different geometry and production characteristics create different conditions for both achievable kg/h and material efficiency.

This does not mean accepting higher scrap because the production mix is difficult or the batches are short. Material losses still require analysis and corrective action.

What matters is identifying their source.

A change in yield related to production structure requires a different response from repeated losses caused by interruptions on dies that are already expected to perform reliably in serial production.

Similar averages can have different causes

Weekly and monthly averages are necessary for managing an extrusion plant. They show trends and make deviations visible, but they do not always explain them.

Two periods can finish with a similar average kg/h while the production behind those results is very different.

One may contain long production runs with a demanding profile mix. Another may contain easier profiles but short batches, frequent changeovers and more additional starts.

The final productivity result may be similar, but the management response should not be.

This is where the underlying production data becomes important. It allows management to separate the effect of product mix and batch structure from implementation activity and interruptions occurring during established serial production.

The KPI shows the result. The production data explains its origin.

Practical performance management

Core production indicators should remain clear and comparable. kg/h provides the overall view of productivity, while scrap or yield shows material efficiency.

At the same time, each profile has its own technological parameters. The objective at profile level is to achieve the most efficient and stable production possible within the defined process conditions.

When the overall plant result deviates from expectations, the analysis should therefore go below the headline KPI.

A relatively small number of questions can provide the necessary context:

• What was the product mix?
• What were the batch sizes?
• How many regular production starts were made?
• How many implementation trials took place?
• How many runs on established dies were interrupted?
• What happened to material yield?

This approach is particularly useful when comparing shifts, production periods, presses or different extrusion plants. It helps distinguish between a result driven by the production portfolio and one that requires intervention in the production process.

BMP Factory observations

kg/h remains one of the fundamental measures of aluminium extrusion productivity. Scrap and yield provide the corresponding view of material efficiency.

The value of these KPIs comes from understanding the production behind them.

Product mix and batch size define the conditions under which the press operates. The actual production sequence adds another important layer: regular starts, implementation trials and interrupted runs on established dies should not be treated as the same event.

A practical management system should keep the headline KPIs clear while providing access to the underlying production data when a result needs further analysis.

Not to justify a weaker result, but to identify its cause and take the appropriate action.

The objective is to achieve the best possible combination of productivity and material yield within the actual production mix, while reducing avoidable interruptions and unnecessary process restarts.