This is a question that we have received in the past so we decided to address it here in the help section! If you are familiar with what a bill of materials is please scroll down to the bottom for some helpful links.

 

In simple terms, a Bill of Materials (BOM) is a list of items that when purchased, made, and assembled, will form your completed project. If compared to cooking a meal the BOM would be the shopping list with notes that details what ingredients you need, how much of each ingredient you need, and even where to get them from and how much they cost.  Whether you're building a smart phone or a dumb toaster, your bill of materials will be the ingredient list for your project.

A BOM may be structured to represent the project hierarchy (e.g. with parent assemblies and subassemblies), or can be flattened to a one-line-per-unique-part structure. A BOM can be as simple as the names of all the parts that go into an assembly to as complex as you particular requirements demand.

A good BOM will usually contain a part number or identifier, the quantity, revision code (number or letter), and material (for manufactured mechanical parts, and some electrical parts); they can also contain as much metadata as tolerance information, author information, reviewer information, vendor (and alternate) information, and other critical to quality fields.

The bill of materials is vital to any manufacturing venture because it is how you know you are building the right thing, or at least, the thing you intended to build.  A good BOM keep tracks of what goes into the product, and provides a way to communicate what you want to vendors in as much detail as possible. The BOM makes sure that you get exactly what you want as long as it is done properly. If you include every detail including units of measurement as well as weight and material then this leaves nothing to the imagination of the vendor and it makes sure that everything you receive is up to specifications!

If we go back to our cooking analogy the importance of a good shopping list is imagine that the friend that is cooking is the one that knows how it will all go and fit together, but they send you to the store. On their list it just says meat, or even more specific it just says chicken. So you go and purchase chicken wings along with all the other ingredients. When you return back to the kitchen and deliver the goods they mention that they were planning on using chicken breasts in the dish and everything else in the cart was for that. 

Now they have all these ingredients that may not work together and there are complications. It's not your fault because the list simply said chicken, not chicken breast. This situation is not uncommon in manufacturing when your BOM is not properly specified.

During the design of a product, especially if you are machining parts, it is important that everything fits in properly and is made of the proper materials. Imagine making all of your calculation in inches but the manufacturer uses centimeters? Or if you need specifically need a part to be made out of iron but since it is not specified they deliver something made of copper? Or your design assumes aluminum capacitors, but you don't specify capacitor material and your PCB assembly vendor decides to give you tantalum? These things can bring unwanted delays and costs, or cause critical product defects in the field, all of which result in lost business opportunity, customer satisfaction, and possibly worse.

 

Bommer helps facilitate the process of preparing a bill of materials without leaving your CAD environment. It makes it easy to keep track of the data that goes with each line item in the project and what information is still needed. You can even add your own columns of data to Bommer in case there is a special property or set of properties that you need added to the Bill of Materials. 

We make it so that the engineers can focus on making cool products and take away the manual labor that generally goes into making a proper BOM. Not to mention it also helps reduce human error that can come as a result of copy and pasting endless amounts of data into excel sheets. Leave the dirty work to us and keep rocking on.

 

If you want some more comprehensive information about what a BOM is then we have some additional resources for you. 

First we have an article written by our very own CEO, Jesse Rosalia about what is a good BOM and why is it important. This can be found here.

If you would like a crash course on what a bill of materials is then our friend Scott Miller at Dragon Innovation has just the clip for you below.