5 Steps to Reducing Design Change Problems

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.

  1. Engineering change request:
  2. 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).

  3. Getting everyone informed/updated:
  4. 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.

  5. Proceed only when you get the “all clear”:
  6. 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.

  7. Change Review Board notification:
  8. 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.

  9. And Purchasing?:
  10. 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.

19 comments on “5 Steps to Reducing Design Change Problems

  1. AnalyzeThis
    October 12, 2011

    I think these are some good guidelines and practices… I think organizations that attempt to run a less “formal” version of this system will be far more likely to have issues: there are indeed valid reasons to have all of these procedures in place.

    And again, I think the real challenge here is getting everyone to always follow these steps (especially engineering… no offense!). There's a great need to educate everyone that each step is critical and failure to follow them could lead to some very expensive mistakes being made.

    October 12, 2011

    I found your article very interesting.  Do you believe a company needs to implement such a system only after it reaches a certain size?  I cannot imagine such formality would be required by a 5 person company for example.

  3. Mr. Roques
    October 12, 2011

    I assume the process will become MUCH clearer once a company suffers from their first big design change issue, literally but also, management will see the value off adding these extra steps that (probably) slow down the production time.

  4. _hm
    October 12, 2011

    This is very good and proven procedure for large organization. What is simplified procedure for small organization? Do you get any off-the-self software package for this?


  5. saranyatil
    October 13, 2011

    I think there must be some tools available not sure but there is a tool to manage these action points.

  6. Daniel
    October 13, 2011

    Now a day’s most of the design/coding works are done parallel across terminals and peoples. So there are tools, where all the designers are working on their own image of the project file. After the individual design works, the tool merges all the images to the project file and finally the system simulation happens. All these things happen automatically and the designer won’t to be get worried about such overlays and issues.

  7. elctrnx_lyf
    October 13, 2011

    yes, generally you get to see the probelms only when the organization is big where fact to face communication of all employees is a time consuming and near impossible task. So such process will simplify the operations and avoids any wrong things.

  8. dalexander
    October 13, 2011

    In a small start-up company, there are usually highly motivated, dedicated, and committed individuals that are capable of multitasking across various engineering disciplines. Throw in the years of combined experience and you have the heightened potential of avoiding historical pitfalls by introducing individually created and managed records in the earliest stages of R&D. These controls may be minimal but comprehensive enough to create an audit trail for the significant efforts and paperwork required to reconstruct the entire development process up to any particular point. The PCB Version 1 Cad files with a netlist exported to a spreadsheet could be sufficient for early BOM management. Cad with Gerbers for early Fab records along with the Engineer's lab notebooks might be sufficient for layout and test strategies. Meeting notes from concept reviews, design reviews, business roadmaps and Materials records such as Purchase Orders, Packing Slips. Invoices etc. could be archived at individual contributor locations or kept on a shared server for universal access. But the earlier the documents are numbered and dated with some kind of revision control and sign-off procedure, the fewer errors will be occassioned by non-comprehensive communications, human error, and repeats of  corrected deisign or part problems only mentioned at the verbal level. As many start-up veterans can testify, you can take a company only so far with spreadsheets and individually managed databases. The sooner the company institutes the basic documentation control procedures, the less problematic the company's infrastructure expansion and product developement will be. A good rule to remember is if you are making more than one revision of the same document, you should begin your documentation and version control procedures immediately. Lastly, no document should circulate through a company without being dated and signed by the author.

  9. Clairvoyant
    October 13, 2011

    The ECR process is a component of the ISO standards. Having processes like ISO 9000, 9001, etc implemented within a company can make things operate much more smoothly and organized.

  10. t.alex
    October 14, 2011

    If there is such tool (i believe there is), it should be able to capture the business sense as well, such as the impact of the ECN (how much cost and benefit such change can bring about)

  11. dalexander
    October 14, 2011

    T. Alex, Very true statement. If you refer to, go to procedures and guidelines, select ECO procedure, you will see under section 5, a cost consideration, and on the flow chart on the same document, item 9 and following page, further procedure for classifying cost impact. Under the Forms tab, select ECN and note that the routing approvals include Finance. If a change is made without considering cost tradeoffs, the company may actually lose money rather than choose a more optimal remedy. Your comment is spot on.

  12. dalexander
    October 14, 2011

    Clairvoyant, I include a Component Engineering ISO procedure on my website. When I wrote it, the team leader for ISO said to remember that ISO was not telling us what to do with our procedures, but to simply document what we are already doing and make sure we do what we say we are doing. The Quality audit only verified the steps we documented. Now, here is the rub, the actual process of documenting what we were doing pointed out the shortcomings of our existing processes, so I am in 100% agreement with your statement when the internal ISO documentation reflects best practices across the industry. In other words, given the same chain of command or employee positions and responsibilities, an ECO procedure at one company should be a drop in replacement at another company. Hence the website has a cadre of forms and procedures that can be freely downloaded and distributed as a jump start to a best practice ISO certification process. Thanks for pointing out the value of ISO certs.

  13. prabhakar_deosthali
    October 16, 2011

    One important link required in the correct implementation of ECNs is to link the engineering drawing data base with the purchase and manufacturing systems. Such link will generate an automatic alert to the in house manufactruing as well as the outside vendors that a new ECN has become effective for a given part and hence a new drawing needs to be used for manufactruing that part.


  14. dalexander
    October 16, 2011

    That is precisely correct. I mentioned earlier that Purchasing does not keep their own drawing file and that every time a new fab is ordered, they must go to Documentation Control and sign out the latest Revision of the drawing and attach it to the hard copy of the PO. The fab house must also not take a verbal order or keep archive drawings. This best practice may cause a little more work on the front end, but it saves a lot of heartache, time, and money in the long run. When the fab shop has restricted access to the fab file server at the company, then all drawings in the form of attachments can be under tight control so the only drawing the Fab house can retrieve is the latest the company has released. If the Fab house tries to download an attachment that has an ECO pending, then they simply cannot retrieve the file. They will be instructed to call their contact at the company to receive any additional instructions, including holding off on the Order.

  15. prabhakar_deosthali
    October 17, 2011

    Thanks Douglas for elaborating on this important point.

    The loop can be closed further by asking the supplier to mention the drawing number and revision number on the invoice . The incoming inspection system should first verify that the correct drawing has been used before generating the RCIA ( receipt cum inspection advice )  for the physical inspection.

  16. dalexander
    October 17, 2011

    Prabhakar, I like it! The final step for quality assurance. Very nice!

  17. Anand
    November 7, 2011

    Do you believe a company needs to implement such a system only after it reaches a certain size?

    @FLYINGSCOT, very valid point. But I feel its always better to have system and procedures in place irrespective of the size of the company because then it would be easy for the company to scaleup its operations.

  18. dalexander
    November 7, 2011

    I am in strong agreement with the premise that the sooner a company puts controls and procedures in place, the better the internal communications, repeatability of product quality, and as anandvy has said, the easier the growth through the development of a solid infrastructure growth discipline.

  19. itguyphil
    November 23, 2011

    Communication between the departments, peers plays a major role in order to avoid problems. These ECR and the remaining steps which are explained in the article may appear in vain by the users, but it largely helps the organization to avoid crisis.

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