Authored By:
Alec Moffat
Product Marketing Manager DPC.
Machine Vision Products Inc.
Carlsbad, CA USA
Summary
In high mix (250+ Assemblies) environments, ensuring small batches are delivered in a timely yet flexible manner without large levels of safety stock and WIP requires the very best of LEAN Manufacturing practices. Dynamic Process Control's (DPC) Material Reservation Manager (MRM) has been designed to provide the tools for major reductions in floor stock and the ability to manage production schedules to maximise utilisation and productivity in this highly dynamic environment.
In line with the current need to dissect volumes into small (<100 unit) Kanban driven batches, using these tools can minimise losses from unplanned changeovers due to missing or un-locatable material.
Any combination of Kanban and ERP/MRP driven order batches can be dynamically loaded automatically in real time. In this example the operators on each of 5 SMT lines perform 'what if's' on each batch. Tracking material reels, matrix trays and sticks loaded on SMT equipment or stored in line locations outside materials controlled storage, we can then check there is sufficient material available to complete the order. If insufficient material is available on the line but is available in material's storage, it is reserved, picked and transferred to the line in time for the orders scheduled start. Shortages preventing production are flagged and the order rescheduled.
Using these tools can reduce waste and eliminate lost time waiting for parts that have been depleted or changing over due to those parts not being available. Every item of material outside of material stores is tracked as it is being used allowing for the application of material FIFO, the use of part used material before new and the real time enforcement of rules such as 'use by dates' and quarantines.
Conclusions
Using a 'what if' approach allows for a LEAN shop floor in what appears to be an almost impossible environment, while not only reducing the occurrence of stock outs to a new 'best in class' level, it directly improves both material and production metrics. On time delivery, throughput, direct material usage variance and OEE have all shown improvement and is expected to continue. Ensuring material can be monitored and transacted real time is no small task, material has to be uniquely identified from its birth at goods received until the reel, tray or stick is depleted. Material attrition must be managed not just measured. But where done correctly the results more than justify the journey required to get there.
By knowing a job cannot be completed or fulfilled before attempting to build, not only can the local losses of changeover and resource be eliminated but identification allows for advance reaction in both upstream and downstream segments of the supply chain.
Total 'Floor Stock' has initially been reduced by 20% with zero impact to the value stream. Ideally we would hope for further reductions as lower demand products are scheduled allowing infrequently used materials floor stock to be minimised. Stock remaining 'on hand' as long as possible improves visibility to MRP/ERP providing a true picture of actual demand and delays consignment material release until it is actually required. This visibly provides the opportunity for reductions in safety stock levels through better understanding of requirements and actual attrition levels. In combination these improvements ensure maximised stock turns and minimal depreciation of floor stock material.
Although shown here in a small volume, high mix environment, 'what if' is equally applicable in high volume, low mix by simply subdividing batches into smaller and easier to manage sizes. More importantly 'what if' removes most of the negatives of using common and pre-loaded setups allowing for more efficient utilisation of capital equipment while also managing inventory turns and minimising depreciation of material.
Initially Published in the IPC Proceedings
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