In a previous blog, I discussed the challenge engineers and operations face when working on a design that may change in the time between when the designers sign off and when purchasing and manufacturing get their hands on the prototype.
In this blog, I offer below critical steps that a manufacturing company needs to take to avoid the problems that arise when many departments and people are involved in the new product introduction process. (See: Keeping Engineering & Operations in Sync.)
Let's add documentation control procedures to the situation discussed in the above blog where — unknown to the purchasing department — engineering has modified a drawing, leading to the wrong purchase order being sent to the fabrication plant. Here are the critical steps for ensuring smooth and effective workflow between engineering, procurement, and manufacturing.
- Engineering change request:
- Getting everyone informed/updated:
- Proceed only when you get the “all clear”:
- Change Review Board notification:
- And Purchasing?:
Engineering decides to modify the part to work across many assemblies. An Engineering Change Request (ECR) is initiated by the individual who is requesting the change. An Engineering Change Notice (ECN) may be used for this purpose with the understanding that at this point the Change Order is a request only and not being implemented until all departments have a chance for input. The proposed change will be supported in the form of an attached, pre-changed drawing with red-lines showing the proposed changes. The pre-change drawing is “checked out” by the engineer from Documentation Control's library.
Note that the purchasing department does not have a private file for documents that are also created or used beyond their own department. This drawing is protected and controlled in one place only. Documentation Control is the official library for all company-wide documents. Purchasing has the procedure in place that mandates every time a fabricated part is to be ordered, it must retrieve the drawing from Documentation Control. When Purchasing requests the drawing, a certified, dated copy is given to it to pass on to the supplier of the part.
The supplier is also instructed to not receive any purchase orders without the drawing being furnished by Purchasing at the time of the order. When a Change Order is initiated, Documentation Control records the date, the name of the engineer taking the drawing for modification, and indicates in its own files that the drawing is in a “pending status” and no longer available to be used by Purchasing or any other department until the engineer returns the original drawing or updates the document revision via an Engineering Change Order (ECO).
The ECR, including all attachments, is routed to all individuals and departments that will be affected by the change. A second party may be assigned to this shepherding process, or a computer may have the function as part of the feature set of the software package being used, but the routing must include the signatures of the individuals who have both the authority and the knowledge to determine the nature of the change and its subsequent consequences as it affects their areas of responsibility.
Once the go-ahead signatures have been obtained, the engineering change efforts may proceed. The cognizant engineer will make the desired changes, update the revision section of the ECO/ECN, and route the change to the necessary authorities for final approval. Some companies will begin this process with an ECR, or Engineering Change Request. This can be submitted by anyone requesting engineering support on a design or procedure change. If Engineering accepts the request, then the Cognizant Engineer will initiate an ECO, or Engineering Change Order, following steps 1 and 2. When the work is complete and the drawings and revisions are brought up to date, the engineer issues an ECN, which is circulated to all relevant departments.
The Change Review Board (CRB) is notified and sends out a meeting notification requesting the attendance of representatives from each department that will be implementing the ECN. Each member signs off on the ECN, and the documentation for the entire engineering change, including all signatures, is checked back into Documentation Control. Old files are archived for historical and support service purposes.
Purchasing is represented on the Change Review Board, and so the company avoids fabricating 500 unusable parts that will end up as scrap inventory.
Documentation Control, in various companies, assumes different responsibilities, including, but not limited to, the following:
- Revision control of technical drawings and PCB Netlist, Gerbers, and special fab Instructions
- Firmware programs and source code
- Mechanical drawings
- Company procedures
- ISO documentation
- Component master specification files
- Silkscreen artwork
- Company quality manual
- Software masters.
In subsequent blogs, I will continue to explore other issues related to the subject of “Essential Engineering and Operations Processes.” Feedback welcome.