Change is expected in electronics development, as new designs incorporate fresh ideas and necessary enhancements over previous products. However, continual modifications to correct problems can slow down, delay production, and cause development costs to escalate rapidly. For the most efficient design development, it is essential to streamline the approval process for engineering change orders (ECOs) and reduce unnecessary and costly ones. Consider the various reasons for ECOs during manufacturing and some methods for managing them.
Engineering Change Order Breakdown
| Who? | The engineer or engineering team will instruct any downstream role (e.g., layout designer, manufacturer, etc.) on what’s changed in the design and how to accommodate it. The layout designer and manufacturer could also inform the engineer of potential issues or changes in the design needs, but the formal ECO will always originate with the engineer. |
| What? | A change to the design after submission of project files, e.g., smaller board size, different component packages/MPNs, DNI components, new circuit blocks, etc. |
| Where? | Whatever communication channels the project team is using, ideally one with time stamps. |
| When? | Any point in production, although more likely to occur early in product development. |
| Why? | ECOs provide a digital “paper trail” of changes made to the design after the initial submission and review of the design document. They can help identify revision history and serve as a legal document in disputes. |
Reasons for Engineering Change Order (ECO) Approval
As products go through their design process, it’s typical to implement design changes along the way. Problems arise when too many changes interrupt the typical development flow or stop the production line. Here are some of the circumstances that can generate ECOs:
- Manufacturability concerns – These changes can range from replacing unavailable parts due to cost or delivery issues to refining the design for efficient manufacturing. Adjustments could sometimes mean moving components around for better solderability or improving how the board interfaces with the rest of the system.
- Performance improvements – ECOs can also improve the board’s electrical performance. A new circuit board often generates too much noise or interference, which requires resolution 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’s also typical for the product specifications to change during the development cycle, forcing a circuit board redesign. The board will likely undergo a significant redesign with new parts and circuitry.
With all of these potential changes during design and manufacturing, the next question is how to keep them to a minimum to avoid costly overruns in the schedules and budgets. Next, we’ll look at some methods for reducing the number of design changes.
Design Workflow and Regular Reviews
Design changes will happen, and many of them are for good reasons. Therefore, it is essential to prevent mistakes and catch errors before an ECO is required to reduce the number of changes. Here are some ideas that should help minimize circuit board ECOs:
Establish a Design Department Workflow
Many mistakes during design originate from a lack of project ownership. By establishing a clear progression of work and defining specific roles and task ownership, an ECO can catch many errors that used to slip through the cracks. This workflow should include all design aspects, from library development to schematic capture, and finally ending with PCB layout.
Engage the PCB Manufacturer Early
Understanding the design rules and constraints your manufacturer will require for the technology you are designing is essential. By establishing these parameters early on, everything in the project, including part selection and design concept, can be aligned with the board’s manufacturing requirements. 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 is manufacturable and operational.
Set Benchmarks for Design Review
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. Start with these four areas of review:
- Parts list
- Schematic completion
- PCB component placement
- Final layout
Partner with an Experienced PCB Contract Manufacturer
A PCB CM with experience in prototyping will know when to incorporate engineering change orders. CMs like this will have specialized engineering and procurement teams that 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 can 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 with you to refine your design and catch any errors, reducing the number of ECOs needed.
