September 8, 2021
By making data available in a targeted manner, processes can be kept stable in the long term. In this way, outliers can be detected and corrected at an early stage. However, if errors occur in the production process, STIWA has been enabling the integration of rework stations in the STIWA control station for many years. With AMS Analysis-CI Rework, comprehensive analysis options are now available live on the HMI.
Rework is a measure to make non-conforming products (NOK) conform again (OK) for delivery to the customer by means of subsequent processing. In principle, avoiding rework is the primary goal in production. However, this is becoming increasingly difficult, explains Alexander Meisinger, Sales Manufacturing Software at STIWA Group: “Technology leaders produce at the limits of what is technically feasible. The underlying processes and dependencies are becoming correspondingly more complex. Increasing customer requirements for precision and accuracy increase the risk of defective parts in the process. In order to avoid rejects or to save NOK parts and components, professional, data-based rework is therefore becoming increasingly important in addition to structured process analysis.”
STIWA optimizes rework
At STIWA, the rework station can be easily integrated into the STIWA AMS ZPoint-CI machine control station. The configuration of rework targets, rework actions or special runs is thereby much easier. Reasons for defects, measured values, batch information, process curves, etc. are automatically displayed, enabling quick decisions in the selection of rework actions. With the rework analysis, these records are linked directly on the HMI with data from Analysis-CI. This can be used, for example, to answer the question of which rework actions have led to success for which defects, or which components most frequently require rework. Another analysis scenario is changes after double checks. They provide information about the reliability of the test stations, for example.
Sustainable cost reduction
AMS Analysis-CI Rework increases the quality of rework sustainably and in the long term. The savings can also be easily quantified, according to Alexander Meisinger: “For a machine with 1 million parts produced and a machine turnover of around 100 million euros per year, a reduction in scrap including rework from 5 to 2 % means a saving of around 4.5 % of the machine turnover already in the first year — taking all production costs into account.”