While changes in our lives can bring many benefits, we can probably all agree that change can be hard. For instance, giving up certain foods made me healthier, but I miss plowing through a plateful of donuts. And while that may evoke some sympathetic laughter, many other changes are more challenging to accomplish, especially if there are financial consequences involved. Take, for example, having to stop the production of a circuit board to incorporate changes into the design.
Change is expected in electronics development as new designs incorporate fresh ideas and necessary enhancements over previous products. But continual modifications to correct problems can slow down and delay production and cause development costs to escalate rapidly. For the most efficient design development, it is essential to streamline the process of engineering change order approvals and reduce unnecessary and costly ones. Here we’ll look at the various reasons for engineering change orders (ECOs) during manufacturing and some of the methods you can use to manage them.
Reasons for Engineering Change Order (ECO) Approval
As products go through their design process, it’s typical for design changes to be incorporated along the way. Problems arise when too many changes interrupt the normal development flow or stop the production line. Here are some of the circumstances that can generate ECOs:
- Design errors: As much as we hate to admit it, even the best of us can make a mistake from time to time. Perhaps we used the wrong part or designed circuitry that was incorrect. Sometimes the errors are created by other problems, such as out-of-date library parts or incorrect design specifications. Whatever the situation, these errors have to be corrected with an ECO.
- Manufacturability problems: These changes can range from replacing unavailable parts due to cost or delivery issues to refining the design for efficient manufacturing. In some cases, this could mean moving components around for better solderability or improving how the board interfaces with the rest of the system.
- Performance improvements: ECOs are also used to improve the electrical performance of the board. A new circuit board will often generate too much noise or interference that must be cleaned up for better signal integrity. Performance changes like these can range from simple placement and routing edits to major re-designs of critical circuitry.
- Functional changes: It is also very typical for the product specifications to change during the development cycle forcing a redesign of the circuit board. With new parts and circuitry that have to be implemented, it is more than likely that the board will undergo a major redesign at this point.
With all of these potential changes during design and manufacturing, the next question is how can they be kept to a minimum to avoid costly overruns in the schedules and budgets? We’ll look at some methods for reducing the number of design changes next.
Design Workflow and Regular Reviews
As we said, design changes will happen, and many of them are for good reasons. Therefore, to reduce the number of changes, it is essential to prevent mistakes and catch errors before an ECO is required. Here are some ideas that should help with the reduction of circuit board ECOs.
Establish a basic workflow within the design department
Many mistakes that happen during design can be narrowed down to a lack of ownership in the project. It often becomes confusing to track who was supposed to do what when multiple people work on the same PCB design. By establishing a clear progression of work and defining specific roles and task ownership, many mistakes that used to slip through the cracks can be caught before an ECO is required. This workflow should include all aspects of design, from library development to schematic capture, and finally ending with PCB layout.
Engage with your PCB manufacturer early on in the design
It is important to understand the design rules and constraints that your manufacturer will require for the technology you are designing for. By establishing these parameters early on, everything in the project, including part selection and design concept, can be aligned with the manufacturing requirements for the board. You will also want to run your design’s part list through the manufacturer’s procurement team to verify their ability to source the necessary components. Additionally, ask for the manufacturer’s recommendations on circuitry and layout to ensure that your design can be manufactured as expected and operate as designed.
Set specific points during design for reviews
One of the best ways to reduce the number of ECOs involves establishing specific reviews while the circuit board goes through its design cycle. The more errors, enhancements, and refinements you can catch before going to production, the fewer engineering change orders you will need later. As a start, these four reviews are recommended, but you can certainly add more as necessary for your specific workflow:
- Parts list
- Schematic completion
- PCB component placement
- Final layout
Another helpful tool to reduce ECOs is working with a manufacturing partner who has experience in building the type of board you are designing. Next, we’ll look at some reasons why this is important.
Partner with an Experienced PCB Contract Manufacturer
Compared to a regular production build, circuit board prototypes and new product introductions typically have the most ECOs. Due to their need for quick changes as designers refine and enhance the circuitry and functionality, these designs often go through rapid-fire changes while they are being built. Many PCB contract manufacturers aren’t equipped with a workflow or a business model to handle this type of work. It is vital to align with an experienced manufacturer for your prototype design.
A PCB CM with experience in prototyping will know what to ask concerning your design changes to ensure that they can efficiently build the design. CMs like this will have specialized engineering and procurement teams seamlessly infuse changes into the manufacturing process without causing significant interruptions. On the production floor, the CM’s technicians will be experienced with a high-mix manufacturing environment and will be able to streamline your changes into the project with minimal impact.
At VSE, we have built our manufacturing business around the high-mix, medium-volume production model. This model has enabled us to refine our capabilities to respond to your change requests quickly and efficiently. We will also work ahead with you to refine your design and catch any errors, reducing the number of ECOs needed.
