Quality and productivity guaranteed as poka-yoke
Functions as poka-yoke
Optimal manufacturing requires high quality standards to be maintained. This is to be arranged in the ongoing process using targeted error management with poka-yoke.
The overall production must be transparent so that each individual step can be identified. In order to prevent errors, typical weak points can be identified early and counter measures can be taken.
This provides production safety and enables rapid correction loops and prompt adjustments when facing changing requirements. This transparency and flexibility is guaranteed by appropriate sensor technology.
The poka-yoke process: Identify, implement and check
Step 1: Identify problem areas
Typical error sources include missing or incorrect parts, insufficient evaluation of colours, a defective assembly process or even manual data entries and machine configurations. These must be determined or anticipated.
Typical weak areas
|Are all parts available and have they been correctly selected?||Have the parts been correctly assembled?||Are the threads fully completed?||Are all of the colours correct?|
Step 2: Implementing error recognition
To prevent errors, check sensors and vision systems and check whether all process steps have been carried out correctly.
Compare position, colour and material
If items are requested and their position is to be checked, sensors are used to measure the position and distance, for example. As such, linear transducers monitor correct tool positions and magnetically coded position measurement systems check all rotary movements.
Photoelectric sensors recognise the appropriate colour, the correct material or any texture differences. Using vision sensors, different test tasks can be carried out in a single control step. They reliably detect whether a part of the characteristic is present or missing and check its position and dimensions, and verify different codes.
|By matching patterns (horizontal, vertical and in 360° rotation), BVS vision sensors check whether bearings are present and check their distance.||Linear transducers monitor correct tool positions.||A BVS vision sensor carries out various tasks in a single test step|
Step 3: Managing deviations
If the tested object deviates from the specified prototype, there are three possible processes for managing the deviation: Rework, reclassification or rejection. RFID systems are used to do this.
RFID records every process step in full: All manufacturing parts used and all materials and equipment used, including time, place and process. This implementation, process and source information is documented automatically.
All information is available in real time. This enables tracing and corrections to be made to the on-going process without any interruptions. Faulty products are removed: Reclassified, reworked or rejected. If they are reworked, they are returned to the production process. Steps that have already been completed are skipped.
This traceability creates lean production processes, simplifies just-in-time deliveries and ensures product quality. This is because RFID offers transparency, meaning that you have a complete overview across all levels.
RFID ensures faulty products are removed so that they can either be reworked, reclassified or rejected.