Manually creating BoMs is a tedious, error-prone process. It doesn’t have to be.

The bill of materials (BoM) is the primary conduit for transferring design data from engineering to purchasing and manufacturing, and it is therefore critical that it be complete and correct. That’s about the most obvious statement ever in our industry, yet BoM errors occur far too often. It would also seem obvious to get the BoM right the first time, yet many companies tend not to, and instead deal with problems in a reactionary mode. These firefighting exercises consume far too much time and effort.

Part of the problem is that many companies don’t have a defined BoM creation method and instead allow design teams to manually create their BoMs. Engineers are a very smart bunch, but we’re not always perfect when the job is detailed and tedious. I, for one, have even more problems with “detailed and tedious” if I don’t have my reading glasses handy, so it’s not surprising that different part numbers look the same, R6 becomes R8, fat finger typing, or any number of other problems occur.

One common error is (somehow) getting the part number wrong. It could just be missing a portion that specifies the version of the part, in which case Purchasing catches the error and it’s easily fixed, although still a time delay. Sometimes the problem isn’t so obvious, and before we know it, Purchasing has acquired 10,000 of the wrong part. A simple “j” in the part number mistyped as a “k” can cost many hours of rework, much finger-pointing, mistrust, money and ultimately delayed time-to-market.

Readers of my past columns probably already know what I’m going to suggest as a remedy. I recommend implementing a component information system (CIS) as the first step. All the major EDA players offer one, so it’s just a matter of getting organized and disciplined with component management.

How does this help? For starters, problems with part information need only be solved once. From then on, design engineers use the corrected part, so the corrected part number, description, manufacturer, manufacturer’s part number, etc., are automatically copied to the BoM. No fat fingers, no typos, no reading glasses. BoMs are created based on a user-defined template: All the engineer has to do is push a button.

The CIS empowered schematic capture tool can go further by verifying parts in the design with the CIS. For instance, it’s very convenient to allow an engineer to change the values of components in the process of simulation to get a properly functioning circuit. However, when it’s time to create the BoM, the value of the part must be correct for the part number specified, or else we’re back to ordering the wrong part. That 2.2µF capacitor that should have been a 1µF capacitor could go undiscovered until the testing phase and waste weeks of time. Worse, a part with the wrong voltage rating might pass testing but fail in large percentages in the field, and now we have a company image problem. Having push-button verification of design parts versus database parts is a quick and easy way to avoid these problems.

The CIS can also specify different manufacturers to handle the requirement for multi-sourced parts. When engineering specifies a new part in a design, purchasing will typically find multiple manufacturers for that part. By storing that information in the CIS, the task must only be done once. All future BoMs specifying that part will have the multi-source information required.

Automated BoM generation also helps with getting quantities correct. It’s not uncommon for a design to have hundreds of bypass capacitors, and automation is clearly a big benefit there. But counting mistakes happen with smaller designs too.

Let’s not forget the value of consistency. An automated BoM generation process ensures consistent BoMs from one design to the next. This consistency allows much easier comparisons between design revisions. BoM comparisons between designs are also easier when looking for things like commonly used parts. A new hire in Engineering, Purchasing, or any other department dealing with BoMs will get up to speed faster if all BoMs look the same. Most important, the contract manufacturer or in-house manufacturing team will save time and money if the BoM is easier to read and analyze due to consistent format, organization, and content.

One of our customers implemented the concept of a “no touch” BoM. It previously had identified gaps in its design process that caused costly delays. One such gap was related to manual BoM cleansing and formatting. Cleansing was required to add manufacturing information, ensuring that parts were approved in internal systems and readily available for purchase. Formatting was required to have the right header and field level information for uploading to business systems like ERP and PLM. To solve this problem, the company implemented a CIS that is fully integrated with its business systems. A new part request is also now in place to ensure that placeholder parts introduced by design engineers get approved and added to corporate systems in a timely fashion. These improvements helped the firm implement a no-touch BoM from its schematic entry software. BoMs come out clean, formatted and fully populated with necessary information required for Purchasing and other departments. This is the essence of getting the BoM right the first time.

Manny Marcano is president and CEO of EMA Design Automation (ema-eda.com); This e-mail address is being protected from spambots. You need JavaScript enabled to view it . His column runs regularly.