The manufacture of standard wood products in the United States has become something of an anomaly. Of course there are some furniture manufacturers and cabinet manufacturers that do have a standard product line but even there the trend is towards mass customization.
So, what is the distinction between a standard, semi-custom, and a truly custom product?
There are two perspectives we need to consider:
- Marketing– Giving a product the label “custom” adds perceived value to a product. This designation has been overused but it is valid when the form of a product changes based on customer preferences. Also, a product can be considered custom when a customer can order it in an exact size.
- Manufacturing– Here the issue has to do with efficiency and how we designate a product can determine how we prepare documentation for manufacturing.
If your product line is strictly standard, it’s relatively easy to provide all pertinent information to clients as well as to the shop floor. Compared to the volume of product, the amount of information necessary for manufacture is small. And it only needs to be done once for each product until something changes.
Semi-custom products, such as cabinets available in standard heights and depths and with widths available in 3” increments are referred to as semi-custom. But they’re not really custom products at all; they’re merely an expansion of a standard product line.
When it comes to manufacturing truly custom products, however, things aren’t so simple. Traditionally, most custom shops felt that standardization is something that didn’t apply to them. They handled every job as if it were completely unique. While this approach seems expedient, it keeps custom shops from taking advantage of some cost saving opportunities.
This is why it’s important for custom manufacturers to analyze their products periodically. They need to look for components that are discreet sub-assemblies and that are made up of parts that consistently have the same relationship to one another. Then they need to see how frequently these sub-assemblies occur during a given period of time. It doesn’t matter that these sub-assemblies vary in size so long as the construction is the same. This is where opportunities for increased efficiency can be found.
When these sub-assemblies occur frequently enough, it’s time to take advantage by using parametric modeling to streamline the process of cut listing and CNC programming as I’ve pointed out in previous articles.
So in order for a custom shop to take advantage of these opportunities, they need to change their method of producing documentation. If they’re been using 2-D drafting for shop drawings, they won’t necessarily have to change that part of the process. But then after the shop drawings are approved, they need to be analyzed to find standard types of constructions. Typical standard sub-assemblies include: cabinet boxes, commonly constructed door and window units, modular furniture, etc. These sub-assemblies may also be found in products that are unique to a particular company but are something that they reproduce often.
When these standard sub-assemblies are found, a choice needs to be made as to how to document and produce them most economically and efficiently. A parametric modeling program is usually the best option but which program is best requires further analysis.
There are two types of programs available:
- If these sub-assemblies are cabinet boxes, you may want to use a cabinet program such as Cabinet Vision, KCD Software, etc. just for these products. Generally, you need to produce a good amount of cabinets to make these programs worth the cost but if you do, you can save a lot of time in cut listing and CNC programming.
- If you have sub-assemblies other than cabinet boxes such as door and window units or modular furniture, you should use an engineering program such as Solid Edge or Solidworks. These programs are less expensive than cabinet programs but they require you to create your own prototypes and they have a substantial learning curve.
Whatever program you choose, be sure to see it demonstrated using your products. Beware of “you can do anything with this program” comments from salespeople. Even if it’s true, getting a program to do something other than what it’s designed to do may be so cumbersome that it’s not worth using.
There are some disadvantages to automating parts of a job that need to be addressed:
- First, you’ll end up with two or more separate processes for documenting and programming your product.
- Secondly, you’ll need employees with the skills necessary to create prototypes in engineering programs or you’ll need to pay the cost and maintenance for a cabinet program. You need to consider whether or not the program under consideration will provide enough cost savings to justify these costs.
- Thirdly, you need to keep track which sub-assemblies will be taken out of the normal process so that everyone involved knows and remembers. Otherwise, the standard sub-assemblies may be either duplicated or left out of the job.
Some larger custom manufacturers have changed their method of drawing along with their documentation completely. Instead of using 2-D drawings for shop drawings and then using an engineering program to process the documentation of standard sub-assemblies, they use the engineering program for their whole mix of products. There are at least three good reasons for this:
- Only one method of documentation is needed so confusion as to which method is being used for a given sub-assembly is eliminated.
- Documentation can be driven by the model itself. For example, when the model changes, the cut list updates automatically.
- This capability can be extended to other aspects of the business such as part labeling, purchasing (Material Requirements Planning [MRP] systems), etc.
- Other capabilities of an engineering program are helpful:
- Interference detection can show where one part is not fit correctly to another part
- Materials can be analyzed for strength, weight, etc.
- Animations can simulate how movable parts will work
The disadvantages are:
- Shop drawings require more time to create.
- Finding and training draftsmen capable of using engineering programs is more difficult.
- Substantial changes in design are more difficult to implement.
So, this may not be the best option for smaller shops or shops that produce few standard sub-assemblies.
But for medium-sized and larger shops, finding these opportunities to cut costs may well be worth the investment.