Das Umrüsten von Maschinen dauert oft länger als man denkt. Umso wichtiger ist die konsequente Rüstzeitoptimierung (Quelle: Adobe Stock, Mongkolchon)

Optimize Setup Times with Lean Methods and Manufacturing IT

Time is an important factor in modern manufacturing to increase efficiency because every time the production process is interrupted, a company cannot produce effectively. To keep downtimes as low as possible, scrutinizing unplanned malfunctions and setup times provides an important starting point for optimization. Proven lean methods and manufacturing IT complement each other.

Optimize workflows during setup change

Optimizing selected process steps with moderate efforts is often an important first step. By arranging materials and tools differently, several minutes can often be saved. To make these savings measurable, a Manufacturing Execution System (MES) records machine status postings and also the actual setup time. The comparison of actual and target values provides information to further optimize setup change processes. Lean manufacturing methods offer a structured approach to do this. Let’s take a closer look at two examples:

The 5S method can be used for the workplace (e.g., manual assembly) as well as for setup work. In short, it is about having only those items available at the workplace that the operator really needs („Sort“). It is also necessary to lay out the equipment ergonomically („Straighten“), keep the workplace clean („Shine“), develop rules to maintain the defined condition („Standardize“), and ensure this for the future by means of self-discipline and audits („Sustain“). The result is simple, yet effective: a tidy workplace means that work is conducted much more efficiently, and time can be saved in the long term.

The SMED (Single Minute Exchange of Die) method propagates changing tools within a few minutes. A setup change process is documented by video recording several times, analyzed systematically, and finally standardized and optimized. Activities are „outsourced“ as well as completely deleted from the plan. So-called external activities such as preparation and postprocessing are removed from the actual setup process in a bid to shorten it. This may be done away from the machine or by another employee, depending on the measure. Actions deemed „unnecessary“ are completely omitted from the workflow. By trying out different options, the remaining workflow is improved until the optimum time is achieved. The last and most important task left is to document the new setup change workflow and train the employees.

Learn more about lean methods at Perfect Production (German only).

Deployment of supporting IT tools

A multitude of parameters must be set up for modern machines. CNC machines even need to have complete programs uploaded. This is often performed manually. Here, the user must ensure that the actual and released data are transferred to the machine control (SPS).  Searching for, importing, or entering data and finally checking it are time-consuming processes prone to errors. So is the manual input of setting data and loading of NC programs. Suitable IT tools offer a solution.

Manual input of setting data and loading of NC programs is time-consuming and error prone. (Source: Adobe Stock, Quality Stock Arts)
Manual input of setting data and loading of NC programs is time-consuming and error prone. (Source: Adobe Stock, Quality Stock Arts)

A DNC tool (Distributed Numerical Control) can centrally manage NC programs and data records of setting parameters. A DNC module integrated into an MES is a useful way to eradicate to errors. The integrated DNC module suggests the right and approved NC program or setting data record based on the upcoming operation, articles to be produced and other parameters. The program is loaded onto the shop floor terminal as part of the logon process, saving the operator or fitter from unnecessary journeys. Integrated editors allow NC programs to be compared with previous versions and modified if necessary. An updated or optimized program is then imported back into the MES for approval and automatically available again the next time. The central management of setting data records and NC programs further simplifies the work preparation activities. In daily working routines, depending on the shop floor layout and other general conditions, savings of more than ten minutes can often be achieved for each setup process.

Learn more about DNC and setting data with MES HYDRA X here.

Avoid setup time with an improved planning

Even hugely reduced setup times remain an „obstacle“ in an efficient production run. However, to avoid setup processes by optimizing the sequence of operations is like a walk on a tightrope. For one thing, fewer setup changes mean that more time can be used productively. At the same time, flexibility sometimes suffers as a result of this kind of setup time optimization, since orders are combined to allow larger batches to be produced in a single run. It also increases lead time, builds up unnecessary inventory, and may jeopardize delivery dates. A happy medium would be a setup change matrix in detailed scheduling: setup times are calculated dynamically to align the sequence of operations accordingly. For example, a much shorter setup time can be applied if only a part of the tool used is replaced and not the complete one. A color change is also usually faster to perform than a mold change. Furthermore, if the new color is in the same color spectrum and also darker than the previous color, the cleaning process is usually omitted. Here, time is also saved. The setup change matrix stores the relationships between preceding and succeeding articles and the associated dynamic setup time. Consequently, you can work with realistic setup times in detailed scheduling. Since basic dates and the dynamic setup time are available in detailed scheduling, you can either schedule the operations automatically or manually with optimization to the specified targets.

Detailed scheduling can also support setup time optimization. (Source: MPDV, Adobe Stock, Gorodenkoff)
Detailed scheduling can also support setup time optimization. (Source: MPDV, Adobe Stock, Gorodenkoff)

In addition, a system-generated setup change list informs setters, toolmakers, and employees in the material preparation department when and where a setup is due. Employees can now align their own tasks with the production run, which also saves time.

Learn more about target-oriented detailed planning with APS FEDRA here.

Reduce setup time – increase production

If setup times are reduced, frequent setup processes are less significant. This means, batch sizes can be scaled down and the flexibility of production increases. Now, a greater number of different articles can be produced in a shorter time. As mentioned before, manufacturing IT effectively supports the reduction or avoidance of setup times. If lead times are reduced, delivery times to the customer are achieved at the same time. It also brings along, a reduction in WIPs and a cut in the proportion of time with no actual value added. Ultimately, competitiveness is boosted because the production company can generate real added value for its customers: Flexibility and attractive prices.

When do you start optimizing setup times?

By the way: Textbooks researched for this article were written by experts of the MPDV Group.

Author: MPDV GmbH

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