by Janne Juola, October 14, 2019
Lead time reduction is essential for two main reasons. First, it reduces capital tied into inventories and all other related costs. Second, it accelerates sales by offering shorter delivery times and adaptations to the market changes.
The processing cycle is usually only a fraction of time compared to the phase when material is waiting between processes on the factory floor or in the finished goods stock. Therefore, when there is room for material flow improvement, investment on higher production capacity (e.g., additional machines) has minimal impact to the lead time reduction.
Following misleading KPIs can make the situation even worse. For example, trying to maximize the overall equipment effectiveness (OEE) leads to expensive machines being required to run at all times. However, this approach does not have an impact on the variable costs (machines have already been bought) nor changes in demand. And producing without demand will extend lead times and increase capital tied to the inventories.
Yet, it is still a necessity to monitor the OEE for a bottleneck resource.
The objective is to have the shortest possible lead time for deliveries.
In principle, it would mean producing everything in chronological order. However, this is often not possible in the manufacturing industry, since there are unit processes in between such as ovens and paint shops where the work is conducted in batches. As well as setups and cleanups, which “brake” the process flow. Also, different production and logistical constraints can impede setting up chronological order (e.g., different types of moulds in production or vessel shipment timetables for logistics). These processes affect the material flow and make for a challenging planning environment. In essence, this means orders need to be grouped into batches.
Only if we consider production batches and sequencing together with process synchronization, can we achieve an optimized and feasible plan. And material flow can be optimized using Advanced Planning Systems (APS). For optimizing the material flow, there are a few takeaways to consider:
Depending on the sources, manufacturing companies have value-added time in their production processes somewhere between 1–5%. And during the remaining time, the semi-finished products are in non-value-adding status. Non-value-added time also includes activities that cannot be solved using APS; but based on our experience, even 50% lead-time reduction can be achieved.
The benefits of process synchronization go beyond conventional business benefits. When orders are scheduled to be in-sync at every step of the process, it eliminates lateness and stops firefighting. It minimizes the sense of continuous urgency, relieves stress from every stakeholder, as well as allows bandwidth for more value-added work such us development activities.