We are fast approaching the end of the year. Thank you to all who have participated in the newsletter this year. Your feedback, responses, and ideas have helped to make it what it is today. I look forward to the new year and to all that lies ahead.
For this issue, we will focus on a choice that all contract manufacturers must make.
Inherent to this industry is the challenge of managing documentation and assemblies designed and controlled by outside organizations. Contract Manufacturers must efficiently track and manage changes made by the customer. This makes assembly revision policies an important topic for manufacturers.
According to the last survey, 56% of you set your internal assembly number revisions to match that of the customer. However, 87% of you change your internal revision whenever the customer changes their own, and 50% of you change your internal revision with each internal product modification even if the customer does not change their assembly revision.
Many, if not all, of you have had instances when customer changes created confusion and may have cost your company or that of your customer significant profit from simple mistakes.
For that reason. we will focus on internal product number revisions. It is a subject that many treat almost as an afterthought, but one that can have lasting impact (both positive and negative) on your business.
As always, we look forward to your participation and feedback as you gain new insights and become a more effective provider of Electronic Manufacturing Services.
Sincerely,
David Sharp
ManEx, Inc.
Business Case - Inventory Control
Assembly Revision
North Eastern Company* (N.E. Company) recently shipped the first article for assembly PCA-8596 Rev S and the customer quickly notified NE Company that the assembly did not match the specified revision. NE Company used a manufacturer that had been removed from the AVL.
By policy, NE Company numbers their assemblies to match the customer's assembly number and revision. Therefore, NE Company produced their internal part number 910-PCA-8596 Rev S. Initially, they suspected that the customer accidentally ordered the Rev S and was trying to blame NE Company for producing the wrong revision. However, upon further investigation they realized that this assembly had gone through three updates, but no revision changes, in the last quarter and the most recent update wasn't applied.
This customer was infamous for frequent changes to their products and often failed to update their own product revision with each change. It was common for NE Company to receive four or five revision updates before the customer finally changed their revision. This made it very difficult for NE Company to manage the changes and ensure the product was shipped according to the customer's specifications.
Although NE Company had documentation to support the configuration they produced, they were not interested in arguing with their customer. This was a profitable relationship and NE Company wanted to provide the value added service of allowing those changes, while controlling the product. They needed a method to allow them to track the customer's changes, and ensure that they produced the most current and correct version.
How can N.E. Company allow for product changes and ensure they produced the most correct version? Do they need to change their policy and not try to match the customer's assembly number and revision? What impact will these changes have on their production and how will it affect their communications with their customers?
* Company name has been changed.
Business Case Solutions
In a contract manufacturing environment, there are three main approaches to managing internal assembly revisions...
"Both [our] customer rev and ManEx (XOS) match revisions - always.
[When a customer changes their product but not their revision] we use a [] wild card to make the changes: i.e. customer rev. A, XOS rev. A[1], next change by customer XOS rev. changes to A[2], etc. [while the] customer revision remains [at] A. Doing this lets everyone know that a [] within the Revision is not part of the customer revision."
- Nick, TX, US
We do set our internal assembly to match the customer's assembly revisions.
We don't change the assembly revision if the customer doesn't change their assembly revision, but I think we should.
"With variant assemblies of the same product or rapid new revisions we are finding it hard to ensure we are building to the correct spec. The only revision level we can rely on is the customer's own but unfortunately many do not bother with one!"
- Peter, Telford, UK
"[We] utilize our own internal revision process, so that we can track changes even when a customer does not change their revision."
"We have found more benefits with the utilization of internal revision control.
"The other part of using an internal revision process is to facilitate internal ECO changes, changes driven by [us], but not necessarily the customer where a customer revision may not change."
- Correen, NH, US
We set our internal assembly revisions to match the customer's assembly revision.
"The benefit is showing what we have built in the past. it helps when looking for a product that the customer is asking about."
- Nick, PA, US
We set our internal assembly revisions to match the customer's assembly revision.
"We are consistent that we are always working from the same page and we cannot get into conflict with the customer who might find that 'you are not on the same rev level that we are'."
- Wayne, OR, US
We do not set our internal assembly revisions to match the customer's assembly revision.
"We change the revision to reflect all product changes to be assured we are making what the customer orders."
- Shep, IN, US
Make YOUR Mark
Please share your ideas and insights on a topic below. Use the questions to direct your response. You can submit your thoughts to mym@manex.com by clicking the topic title. Where appropriate and space permitting, we will post responses in a future newsletter so all may benefit.
ManEx Minute is a weekly email distributed by ManEx, Inc.
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1.1. Business Case Solutions - 14 - Assembly Revisions
Business Case Solutions
In a contract manufacturing environment, there are three main approaches to managing internal assembly revisions. Complete Internal Control, Complete Customer Control, and Combination. Each has important considerations and will be explained below. The approach selected will determine procedures for handling changes and tools needed to manage those changes.
Complete Internal Control -
With this approach, the internal assembly revision is set and updated independent of the customer's assembly revision. For example, all new assemblies will receive an internal revision of 1 (indicating it is the first version of the build). With each change to the assembly (regardless of significance or how the customer handles it) the internal revision will change. This makes it very easy to identify the most updated version of the assembly as well as how many changes the assembly has had since the start of production.
If the customer always and exclusively produces the latest revision of a product, then this method simply requires users to verify that they are ordering and producing the latest revision. However, if the customer orders older revisions, this method may make it more difficult to correctly select the appropriate internal revisions and must have appropriate safe guards in place to reduce the possibility of human error.
Additionally, it can make communication with the customer more of a challenge as employees may use the internal revision, while the customer uses their own revision. This can be overcome with tools to match internal and customer revisions.
Because each change results in a new revision, this approach requires only a method for matching the customer's revision with the internal revision.
Complete Customer Control -
With this approach, the internal assembly revision is set to match the customer's assembly revision. Regardless of how many changes, or the types of changes the customer or company make, the revision always matches that of the customer.
While this method removes the responsibility of managing the revision from the contract manufacturer, it does increase the potential for human error. This is especially true if the customer does not always make a revision change each time they update their product. As with NE Company, it creates the possibility of producing the correct revision, but not the correct configuration.
For this approach to work, users need tools to effectively document when and what changes were made, and processes to verify that all changes have been appropriately and completely applied to the assembly documentation.
Combination -
With this approach, the internal assembly revision is set to match that of the customer, but subsequent changes to the assembly affect the internal revision even if the customer does not change their revision. This is typically done with special characters or notation. For example, if the customer's assembly revision is A, the internal revision might be A.1, or A[1].
This method allows the customer to order any revision of the product and employees to quickly verify that they are producing the latest version of that revision.
Regardless of the approach selected, it should be uniformly applied to all assemblies and customers to simplify processing and reduce the possibility of mistakes.
1.2. ManEx Solution - 14 - Assembly Revisions
ManEx Case Solution
Regardless of the method selected, ManEx has the tools to document and control assembly changes and revisions.
ECO Module - The ECO module allows users to document the source (internal or customer), the purpose, the details, and the impact of the change. The module can apply the changes to new and existing jobs, and ensure that production is aware of the change and is using the latest information. This module works well with any of the three approaches.
Effectivity/Obsolete Dates - The Effectivity and Obsolete Dates allow users to document in the Bill of Material when parts were added and/or removed. This automatically applies the changes to existing orders even if the assembly revision doesn't change. This method is most effective when using the customer's revision as the internal revision, but can be used for any of the three approaches.
BoM History - If the effectivity and obsolete dates are used, then it is possible to check the specific parts list at any given date using the BoM history in the Integrated Bill of Material & AVL module. This method is most effective when using the customer's revision as the internal revision, but can be used for any of the three approaches.
BoM Copy - To simplify changing a Bill of Material, while maintaining the original version of the assembly, users can copy the parts list into a new assembly and make changes as needed. This tool works well with either of the three approaches, but is only needed in the absence of the ECO module.
Relation to customer assembly and revision - ManEx allows users to connect the customer part number and revision with the internal part number and revision. This simplifies communication by allowing users to find the correct internal part number and revision associated with the customer's assembly and revision even if the part numbers and revisions do not match. This works well with any of the three approaches.
Separate assembly number and revision fields - ManEx uses separate assembly and revision fields making it easier to group all revisions of the same assembly and verify that the correct version is selected for production. This works with any of the three approaches.
CONCLUSION
NE Company decided to use the combination approach and utilized the tools in ManEx to control and manage this process. All new assembly revisions are initially set to match the customer's assembly revision. Any changes made internally or by the customer result in either a part number or revision change even if the customer doesn't update their own revision.
This recently allowed NE Company to prevent a mistake. The customer revised their AVL on assembly PCA-8596 Rev T, but didn't update their revision, NE Company created assembly 910-PCA-8596 Rev T[1]. When they received the order for PCA-8596 Rev T, they were able to ensure that purchasing order only currently approved components.
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