Welcome to part three of the article on addendums. It covers a few tips on creating and implementing an addendum in your organization. How to implement an addendum is just as important as the creation process.
This section covers a few tips on creating an addendum. The tips are divided into three parts; useful information, tips for creation, and typical pitfalls to avoid.
The list below contains an example of useful information for creating an addendum. All of the items may not apply to your organization.
The list below contains an example of useful information for creating an addendum. All of the items may not apply to your organization.
The list below contains common addendum pitfall . All of the items may not apply to your organization.
This section covers a few tips on implementing an addendum. The tips include approvals/buy-in, distribution, and training. All of these tips may not apply to your organization.
Hopefully, some insights were gained with this brief look at addendums. As you may have noticed, I am an advocate of using addendums in large corporations. Developing an addendum renews the focus on the importance of drawings.
In a survey I conducted, I found that about 30% of the companies in the survey use addendums (or some sort of supplement to the Y14.5 standard), and about 15% mentioned that they felt an addendum would be useful in their company.
If you would like to see an example of an addendum, you can purchase a copy of the GM addendum by clicking the button below.
Does your company use an addendum? Do you have any suggestions for items that should be in a Y14.5 standard addendum? If so, add a comment below.
If you would like assistance in creating a corporate addendum, contact me at Alex@KrulikowskiConsulting.com
A few weeks ago, I surveyed on whether the ISO GPS or ASME Y14.5-2009 standard is more widely used on drawings in industry. I posted the survey on several group boards on LinkedIn. This article compiles the results of the ISO GPS and ASME Y14.5 standards survey.
Before I discuss the results, I would like to thank all the people that participated in the survey. Their contribution allows all of us to look at the questions in this survey from many users viewpoint.
Since the survey is comparing the use of the Y14.5 (a US standard) and the ISO GPS (an International standard) standards, the results are shown as a comparison of US responses and International responses.
The figure above shows that the International response rate was slightly higher than the US response rate. There were 133 total responses from 27 different countries. The US had 63 responses and their were 70 responses from the International community. The highest response rates of the International participants were from India, Poland, and Brazil.
The survey had participants from a variety of industries.
The survey responses came from employees working in companies from less than 100 to over 100,00 employees. The chart above shows that 53% of the participants work in companies with more than 10,000 employees.
The first three questions of the survey are focused on gathering information about the participants. Their country and the industry they work in and the size of the company. The next section of the article will explain details about which tolerancing standards are used on drawings in their companies..
Whether the ASME Y14.5 or ISO GPS standard is more widely used on drawings is the main question in the survey. My students and customers have often asked me this question. My colleagues in the ISO GPS and ASME standards community talk about it as well.
The survey shows that the ASME Y14.5 standard is widely used (86%) in the US and is used significantly Internationally(56%).
This survey is based on 133 responses from 27 countries. Although the participation is significant, it is not high enough to make an accurate assessment of the use of tolerancing standards in industry globally. However, it does provide us with information to make useful insights on the use of standards even though it is not a definitive answer.
Keep in mind; the question below is asking an opinion of the participants.
When asked, "If your company was evaluating which tolerancing standards to use in the future, what would be your recommendation?"
Most of the participants (67%) responded the ASME Y14.5 tolerancing standard as their preference and both ASME Y14.5 and ISO GPS as their second choice (20%).
The three most common responses from the US participants are below. The standard they recommended is shown in bold. (The number in parentheses is the number of participants with similar comments.)
The three most common responses from the International participants are below. The standard they recommended is shown in bold.(The number in parentheses is the number of participants with similar comments.)
A few additional interesting comments from individual US survey participants are below.
A few additional interesting comments from individual International survey participants are below.
Based on the survey responses, I feel that the survey suggests three things:
I hope you found the survey results informative. If you liked the article, please share it with your friends on Linkedin. Feel free to leave a comment about your experiences with these standards or on any aspect of this article.
For all of my colleagues in the ASME and ISO standards committees, I am just the messenger of the survey responses.
Thanks again to all the survey participants.
This part of the article on addendums to Y14.5 covers the five categories typically found in an addendum.
Throughout this article where a number appears between square brackets, e.g. [xx], it refers to the paragraph or figure that is being modified from the ASME Y14.5-2009 standard.
There are five categories of content commonly found in corporate addendums.
1. Allow the use of only one of several optional methods.
2. Change a default condition.
3. Clarify a concept, symbol, modifier, or definition for your companies' application.
4. Discourage/disallow the use of a concept, symbol, or modifier.
5. Document the use of a tolerancing practice that is not in the Y14.5 standard toolbox.
Examples of modifications in each content category are in the paragraphs below. Corporate addendums may include many or just a few modifications. This article contains a few examples of modifications that are common in addendums.
The format of an addendum varies in each company. The format shown here may not be optimal for your company.
The examples in this article are not arranged in the sequence of a typical addendum. The examples are grouped by category.
This content category is popular in addendums. Selecting an option when several practices are permitted in the Y14.5 standard is important because it helps to create consistent drawings and reduce confusion.
The list below contains a few examples of selecting an option from the Y14.5 standard.
In most cases default conditions are not revised in an addendum; they are addressed on the face of a drawing. What should be in an addendum is a list of which defaults should be overridden on your drawings and instructions on how to override them.
Changing a default can be beneficial because the default may not be the best for your company. For a list of common defaults in the Y14.5 standard, check out the blog article "Do you know which ASME Y14.5-2009 defaults apply to your drawings?") Click here to read the defaults article
If the default conditions are not the same for all types of parts in your company, the addendum should show what parts should have defaults overridden and how to denote the override condition.
The advantage of revising standard defaults on the face of a drawing is that the requirement or condition is visible to the drawing users.
Clarifying concepts from the Y14.5 standard is important because it reduces confusion by providing additional explanation of items that are not fully explained in the standard.
The list below contains a few examples where clarifying a concept from the Y14.5 standard could be in an addendum.
Each ASME standard contains a paragraph citing a list of additional standards it invokes and provides a method to determine which standards are partially invoked.
However, many companies have difficulty understanding exactly which standards, and which versions apply to their drawings.
Discouraging or disallowing the use of a symbol or concept is important because it reduces the number of tolerancing tools available for use on drawings. There are many tolerancing tools in the Y14.5 toolbox that are not needed for some types of parts. There are also tolerancing tools that are not used often.
There are subtle differences between some of the GD&T symbols. There are often discussions over which symbol is better for an application. The addendum focuses the discussions by disallowing or discouraging certain tolerancing tools leaving the tolerancing tools needed for defining your products.
Tolerancing tools can be disallowed for a variety of reasons. A few tolerance tools are overly restrictive for most applications or are not a good tool for your companies' applications. A few tolerancing tools that are only used in rare applications may be disallowed or discouraged to prevent their widespread use.
The list below contains a few examples of disallowing or discouraging a concept, symbol, or modifier.
Another area that I recommend companies to address is to discourage "extension of principle" on their drawings when a tolerance application is not in the Y14.5 standard or in their addendum. Even though the extended principle may make sense to the drawing creator, since its interpretation is not documented, it can be interpreted differently by drawing users.
Documenting the use of a symbol or concept that is not covered in the Y14.5 standard is important. It helps drawing users to have a consistent interpretation of the drawing requirements. If you add a new symbol or concept, it should be fully explained from a functional and inspection standpoint.
The list below contains a few examples of tolerancing tools that are not in the Y14.5 standard but may be needed. In this section, only example topics are listed, the entire addendum text and figures to fully describe these items are too lengthy for this article.
Adding new tolerancing tools in your addendum should be used sparingly. Adding new tolerancing tools can cause problems for CAD, analysis, and inspection software.
In part two, we looked at each of the five content categories of corporate addendums. Each corporate addendum is different based on their unique situation. Every addendum will not address all five of the above categories. An addendum may also include additional information not discussed in this article.
Part three of this article will be posted next week. In part three, you will learn a few tips on creating and implementing an addendum in your organization.
This article consists of three parts. The first part discusses whether using an addendum to the Y14.5 standard is a good practice for your company. The second part explains the five content categories typically found in an addendum. The third part provides tips on creating and implementing an addendum.
If you answered yes to any of the questions above, then you should consider creating an addendum to the Y14.5 standard.
I can read your mind. Some of you are wondering "Why do I need to go through the expense of creating and implementing an addendum when I am getting along just fine using the Y14.5 standard alone?
However, have you considered the following?
The Y14.5 standard is like a giant toolbox with tolerancing tools for all sorts of applications.
Imagine you were in a contest and won a giant toolbox filled with hundreds of different tools. The tools could handle almost any kind of plumbing, electrical, or mechanical repair job that came along. This toolbox has so many tools that knowing how or when to use all the tools would be difficult. The giant toolbox is good because you could use the tools that you are familiar with to do many jobs. It would also be bad because there would be tools that you were not familiar with and you might end up using them in the wrong places. The Y14.5 standard is similar to the giant toolbox.
The Y14.5 standard includes tolerancing tools for many applications. Having a standard that is like a giant toolbox is useful because it provides tolerancing tools that are needed for most applications in many companies. It also can be confusing because it contains tolerancing tools that are not useful in a particular company. This toolbox approach requires users to choose from several tolerancing tools to select the one that is best suited for their application
Which tolerancing tool is best for my application?
The Y14.5 standard contains many options and over a dozen defaults. In some cases, it provides multiple ways to communicate the same requirement. The Y14.5 standard also has a few tolerancing tools that need to be explained in more detail for some applications. There are also cases where there are tolerancing tools that are needed in a particular industry but are not covered in the Y14.5 standard.
An addendum can improve the use of the Y14.5 standard and guide users in creating drawings that are clear and consistent. An addendum is of particular importance for companies working Internationally due to the variations between ASME and ISO standards.
An addendum is a document that supplements the Y14.5 standard. It may also supplement other ASME standards as well.
In some companies, an addendum exists under other names like corporate standard, engineering standard, or another name. If your addendum documents a change to a default condition or adds a tolerancing tool, not in the standard, the addendum must be referenced on each drawing for interpretation. In this case, your addendum must also be accessible to all drawing users.
The word "addendum" is a bit misleading. An addendum does not only add new tools; it can also reduce or limit the tools based on corporate need. Most addendums result in a smaller more focused standard. In fact, many addendums contain very few new tools and mostly clarify existing tools, select options, or limit the tolerancing tools in the Y14.5 standard
Although this article, for the most part, discusses an addendum to the Y14.5 standard, however it is common for addendums to encompass additional standards.
An addendum can provide many internal benefits to a company as well.benefits when working with suppliers
Five benefits of using an addendum are shown below:
Part one of this article covered several aspects of corporate addendums. It defined what is an addendum. It also discussed why you should consider using an addendum and highlighted five benefits of using an addendum.
Part two of this article will explain and provide examples of the five major content categories of an addendum. Part two will be published next week.