Here at FourJaw, we speak to manufacturers running small-batch production on a daily basis.
In these production environments, a batch of 10 components is considered high volume, and one-off jobs make up a significant quantity of the work.
The types of industries these small-batch manufacturers serve varies hugely, but the same question keeps popping up…
“How can we implement continuous improvement when we are working with different fixturing, tooling, component geometries and materials every day of the week?”
The truth is, the small-batch shop floor is one of the hardest places to implement continuous improvement. In a high-volume production line, it is possible to look at the outputs over time and refine the production process through an ongoing feedback loop until it’s a finely-tuned operation.
In the world of small-batch, that feedback loop isn’t available. These businesses need to work much smarter to achieve world-class productivity whilst delivering a diverse mix of work.
CAM Workflow Optimisation
Since small-batch manufacturers can’t optimise production at the level of an individual component, they need to move up one level and optimise the machining workflow. A great example of this is how we program our CAM toolpaths. Let’s imagine our shop floor does a lot of work making simple 2D profiles from plate metal.
Using on-machine programming, each component has to be programmed up individually, and whilst this is happening, the spindle is not running, causing decreased productivity. By moving to off-machine programming with a CAM package, and applying generic templated toolpaths, (https://www.youtube.com/watch?v=feBEu41V4U0) every job involving a 2D profile now goes through the same unified workflow. Even better, we can apply the continuous improvement process to this unified workflow to drive further efficiency gains. This approach also holds for more complex operations such as deep hole drilling, 3D surfaces and even 5-axis machining.
Streamlining our CAM workflow allows the spindles to be turning for longer, and gives better accuracy in the quoting of work, pushing our business to be more profitable and competitive in the global marketplace.
Production Schedule Optimisation
We’ve all seen examples of a poor production schedule, and the tell-tail sign is often the length and frequency of setup/teardown work. It’s all too often that the production schedule is created in isolation, becoming a theoretical masterpiece that just doesn’t work on the shop floor.
This can lead to the same fixture being mounted and removed several times over the course of a week to serve different jobs, when those jobs could have been scheduled back-to back to minimize fixturing changes.
Splitting up batches is another common symptom – for example, when a production run of 20 components is split into 2 runs of 10 components interspersed by other work. This doubles the first-off inspections, doubles the setup time, and can also have implications on the consistency of components across the batch.
The solution here is to improve the communication between shop floor staff and those who do the planning. When the birds-eye-view of lead times, batch sizes and production capacities is combined with boots-on-the-ground understanding of the machining process, only then can we achieve an effective and pragmatic schedule, that works as well on the shop floors as it does on a spreadsheet.
To catalyse this, a weekly meeting between production staff and management can be highly effective. An hour spent together planning as a team can result in many hours saved in efficiency gains throughout the week. Here at FourJaw, we have seen a key predictor of the success of a machining business is whether or not it creates a frequent dialog between management and production staff. Where this dialog exists, production improves and the business is all the better for it.
Shop Floor Environment Optimisation
At FourJaw, we help machining businesses understand what is happening on their shop floor – we strive to tell the story of what your machines are doing throughout the day. A key part of this is quantifying the main reasons for spindle downtime.
It’s attractive to think that productivity improvements are all about in-cycle optimisations of speeds and feeds. This certainly has a place, but from our experience, the low-hanging fruit typically comes from optimising the shop floor environment.
Simple things come up time and time again, like searching for a set of missing allen keys, walking across the factory to fetch a dial gauge, queueing for first-off inspection, or waiting for the shop floor crane. Each of these costs 10 or 20 minutes of machining time, but when it happens multiple times a day across all of your machines, the end result is a huge factory-wide drop in productivity.
The first step to optimising your shop floor environment is to quantify when your spindles are stopped, and what the main causes of the stoppage are. From there, you can have an open discussion about what you can do to improve the shop floor environment and keep those spindles turning for longer. In a lot of cases, you may be pleasantly surprised about how simple, quick and cheap the solutions can be. Sometimes, a new set of allen keys is all it takes to up your productivity!