How Does a Car Get Painted aka APS in Paint Shops
You come into the showroom, the salesman hands over the keys and you step up to your new car for the first time. The paint literally shines, and you look forward to the rev of the engine. But do you know how it got painted? And that it’s definitely not just one quick job after assembly? Paint shops are very complicated operations, and we’d like to describe them to you.
It has long been the rule that new cars are not made entirely at the automakers. Hundreds of other firms specialise in producing the individual components, and if these are components that affect the car’s visuals, then painting awaits them as well. It’s a process that’s definitely complicated to plan, because every error means huge losses of both time and money. Because not all blues are the same, and because you can’t just spray black paint and then immediately switch to white. But despite this, all of the parts have to arrive at the automaker in the precise order that they’ve dictated. So, if a request arrives for delivery in the sequence red, white, blue, black, you have to use precisely that sequence when delivering your products (e.g. bumpers or doors, which are typically manufactured externally). How do you plan all that?
Skid, Jig, Primer, Colour System – Do You Know Them?
First let’s explain a few terms. Just like every area, the paint shop has its specialised expressions:
- The Skid (or also the SkidType, ST) is a metal construction with hooks (called jigs) upon which painted parts are suspended. Different quantities of parts can be suspended from a single skid, depending on their size (e.g. 1 bumper vs. 1,000 caps).
- Painting Train (PTT) – a table with a breakdown of the individual SkidTypes.
- Colour System (CS) – the paint loading for the painting robots.
- Double Paint (DP) – two-round painting, first with the Primer and then with the surface paint layer.
Magna Liberec – Skids. Source: lidovky.cz.
Prohibited Colour Combinations, Rinsing etc.
The main difficulty faced by all paint shops is a large number of restrictions. To put together an efficient and realistic painting plan, they thus need to take into account all capacities, equipment limitations and manufacturing processes. Without planning tools, this is practically impossible. As we mentioned in the introduction, there are many minor details that fundamentally influence the final product. For example, the colour. Not all blues are the same. Every automaker has its own precisely defined colours, and even though they can seem very similar at first sight, you definitely can’t substitute the colour that Audi uses for the one used by BMW. And then there’s prohibited colour combinations. You simply can’t just paint in red and then immediately paint in white. Although painting devices do get rinsed, the result would not be ideal. And there aren’t many light pink cars out there on the streets… Meanwhile, the method for suspending the products on the skids (one-sided vs. two-sided) also plays a role, and so on. Thus, when composing the plan, a strong emphasis is placed on configuring it precisely to match a specific paint shop’s operations. Advanced Planning & Scheduling (APS) systems are what is used for planning manufacturing processes that are this complicated. These enable the production line to respond even to cases that would be nearly unmanageable without them. By this, we mean non-standard situations such as quick re-planning due to downtime, as well as urgent orders by the customer. APS also makes it very quick and simple to respond to material availability and the need to re-hang skids.
So How Do You Plan It All?
If a company’s management decides to implement APS, they first need a thorough mapping and analysis of their processes. During these, bottlenecks are determined, as well as the skid sequencing logic and the differences between individual plants (if the software is being deployed at a company with multiple branches). One secondary process here is the sanitising of all input data (methods, bills of materials, item and supplier masters etc.). This is followed by the creation of a planning model, which is tested on real-world data. The result is a unique tool that ensures that production will go smoothly.
We are helping one of our clients to plan cap production in what is by now a third plant. The program in charge of both paint-shop planning and the actual production and subsequent assembly of components is the Asprova APS. This system is unique in that it has predefined solutions that do not need to be reprogrammed, enabling us to prepare a planning tool relatively quickly. Yet despite this, when configuring Asprova for paint shops we’ve run into areas that are specific for precisely this field, such as Prohibited Colour Combinations. As we’ve mentioned, you can’t just paint in red and then immediately in white – and that’s not the only such combination. The application needs to incorporate these restrictions as well.
Another Asprova function is grouping into painting units. The goal here is to prevent the situation where, during a sequence, the plant starts painting with a colour that isn’t ready, and at the same time to create a report for the paint exchangers. Exchanging the paint in all systems takes varying amounts of time, and can even reach up to several hours. That can mean very long idle times if things are not planned correctly and/or the operators of the paint exchanger do not receive the correct information. And then there’s the very special Double Paint. In this process, the same part is sent to the paint shop twice. In the first round, it’s painted with the primer, and then it’s placed into the work queue a second time, this time for its final paint job. Not all parts are sent through Double Paint, and the production plan needs to take this into account as well. The system precisely defines at what position (what jig) a part needs to be suspended for re-queuing after its first paint job. It’s thus important that every site have access to reports that display the work queue clearly and simply. The production supervisors and the planners themselves each have their own outputs from the system. Asprova thus ensures that all sites work with the same data and have precise information for their activities.
As you can see, manufacturing an automobile, and then painting it on top of that, is no simple matter. Will you look at your car the same way after today?