Evaluating the Pattern Grading Process

Last week I wrote about the pragmatic “Technical Journal” formerly published by Bobbin Magazine. I didn’t get much feedback in response to the index of articles (pdf) I compiled which was a little disappointing considering all of the work it took to put it together. Complain complain, I know. Still, a few of the responses mentioned Evaluating the Pattern Grading Process as being of interest which is what I’m writing about now. The article consists of responses to seven questions. I thought to do this in one fell swoop but decided against it once I realized that some items will need more discussion and weight than was given in the original material. First I’ll include all of the questions and then go back and address each in turn as some get a little sticky. Then again, if nobody responds, I’ll just let it go.

  1. Have you converted your pattern grading from a manual operation to a computer grading operation?
  2. Does your grade rule library consist of an unusually high number of grade rules, many that you may have used only once?
  3. Are you satisfied with the time period that is required from the time the grader receives the sample pattern until the final approval for production is given?
  4. Are you grading properly or have your methods been handed down and modified from one grader to another until the grading process has become a “guess again” situation?
  5. Are your production people free to make suggestions on changes that would aid them in production?
  6. Do you have documented procedures that are followed with every pattern that goes through grading?
  7. After I’ve evaluated the situation and want to straighten it out, to whom should I return for professional advice?


1. Have you converted your pattern grading from a manual operation to a computer grading operation?

The article’s author (Thomas R. Jones) first cites the common strategy of managers who think that throwing money at the problem (investing in a CAD system) can fix the problems but correctly states that this couldn’t be more wrong. A CAD system simply permits faster implementation of your practices. A CAD system is not a solution if the manual standards and system you were using before are not sound. A CAD system “will will just allow the damage that was being done to be done in less time”.

To that I’d add that assuming mistakes are made, the faster cycle time of CAD systems provide opportunities to spot errors and inconsistencies much earlier and sooner. Time that previously would have been spent with manual grading can now be invested in correcting the problems. Previously, it is common that several (if not all) pieces are graded erringly before the mistake is discovered. This way, time is spent on the correction rather than the manifestation and creation of the error before it can be corrected. Lastly, having access to computerized grading services isn’t limited to those with CAD systems anymore. Anyone can derive the benefits by using a service.

2. Does your grade rule library consist of an unusually high number of grade rules, many that you may have used only once?

The author writes:

This condition will make itself known if you are continually refining rules as you receive new patterns. Try not to reinvent the wheel every time. Standardize, simplify and document procedures when you can. An unusually high number of rules can be the result of a large number of styling variations (raglan, dolman, fitted, non-fitted). This situation may also occur if you have product lines that require fitted and non-fitted size ranges (SML vs 8,10,12)

I concur with this in some respects although I’d object to the idea that designers should limit their creativity to templated styles in the interests of making grading easier. Even among product lines with a lot of styling changes (the aforementioned dolman, raglan etc), there are grading standards that can be brought to bear. Where I see DEs making mistakes is in what I call vicarious sizing; they routinely switch between SML versus numbered sizing. It is less expensive to grade in SML, so if a designer’s signature styling lends itself to that, then that’s great. Higher priced product lines with more fitted styles may not have that option. Regardless, I think a designer should select one or the other sizing strategy based on their silouhettes until such time that their line matures and they see fit to expand their offerings.

3. Are you satisfied with the time period that is required from the time the grader receives the sample pattern until the final approval for production is given?

The author mentions a turnaround time of one week but this assumes you’re doing everything in house. He says that your people must have the right equipment (dress forms, sewing equipment, rulers, curves, tables). He also mentions a facet profoundly ignored these days “if you’re not sewing the graded garments on site, you are likely to lose valuable input from production people as well as those days and dollars it takes to ship the patterns back and forth”. These days, delays are often unavoidable for DEs and multi-national alike. Generally the point is made that the more integrated and closer you can have your product development, the better and faster it will be.

4. Are you grading properly or have your methods been handed down and modified from one grader to another until the grading process has become a “guess again” situation?

Other than the obvious -the lack of standardization and documentation of in-house grading standards, the author wrote some disparate ideas (competitive foreign challenges, the costs of training, modernization) but I give those lesser weight than the immediate. The reality is, people will come into your system and both of you will have expectations of guidelines. You will have expectations and they will need parameters. This usually means they will be using a legacy system that preceded them, no matter how poorly formed, upon which to render work. Now, as someone coming into the system, unless you’ve given them carte-blanch to change things, they will be using precedent standards which won’t necessarily be a good thing. As is often the case (because designers start off poor and hire what talent they can afford) these legacy standards may need revising. Even then, it is possible you’d be guilty of a bad hire, someone who’s sold you on their ability to do the job when they’re largely unskilled and so, change the standards to meet their limited knowledge. It’s a tough situation.

This last topic is something I think bears some discussion. If there is any interest, we can flesh it out in comments or I can include it in part two (questions 5-7) depending on the response.

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15 comments

  1. Esther says:

    I find grading an interesting topic, just not sure who else would be really interested. I have received few comments on my own grading blogs. Just a few comments of my own.

    2. No one should be restricted to a set limit of grade rules, meaning the rules that define the X,Y changes of each point around a piece. This makes more sense in a CAD situation because each point can be more easily manipulated. The number of grade points/rules is dependent on the number of pieces in a given style and the finished measurement requirements. In a CAD situation, it is easy to add a grade point anywhere on a piece to control growth. Always double check the finished measurements of a style in the largest and smallest sizes of a range to make sure a piece has been graded properly.

    3. Again, in a CAD situation, it doesn’t take much more work for a patternmaker to also grade. A CAD system allows a patternmaker to grade a style in the fraction of the time it takes to do it by hand. Most pieces are stored in the system already graded. A finished style will only need minor tweaking.

  2. Karen C says:

    Re: topics we would like you to explore from the index of articles. Just had a chance to peruse the index and I would be most interested in garment dyeing, fusing and pressing and finishing. Would also like some feedback on the 3 articles on training sewing machine operators. (Really, I love to read and learn, and would love to own the mags.)

  3. Babette says:

    I’m with Kathleen on the number of grade rules.
    In a CAD system, it’s no issue to store additional grade rules, libraries etc. They may only have been of use once – use the comments or notes facility to remind yourself what it was for and why and why you aren’t using it now. It’s institutional memory and learning. And maybe, with the fashion cycle, you’ll be back to using it in five or six years. Who knows.

  4. I say that anything and everything you put on this blog is way cool and informative, so just keep it up! :-)

    Even though I did some grading in school and I look at the home sewing patterns I have, I would say that grading by hand or computer would depend on what works for that company, as long as they definitely make sure that the garment “grows” right. But I’m not an expert and haven’t read the Book yet. :-)

    I’d like to know what they say about training sewing machine operators and how that differs from basically just teaching someone how to sew. At least from the point of view that I’ve been sewing for just over 20 years, but I learned tips and tricks on the industrial machines when I was in school.

  5. colleen says:

    In addition to Grading, I would like to review the journal articles on: Quality, the Key to Profit; Balancing Inventories: Matching Expectations to Realty and Quality, Cost and Schedule.

  6. Ellis says:

    Well I have a “After I’ve evaluated the situation and want to straighten it out, to whom should I return for professional advice?” question…

    We recently had a Japanese company want to return $1,500 worth of merchandise claiming that our garment did not meet the minimum neck circumfrence to go over a childs head. The item has no problem going over a childs head and our company has sold this same item for over 4 years and this is the first time anyone has ever mentioned anything about this. They go on to state that the Japanese minimum neck opening standard is 20″ for infant and 22″ for toddler. I have always made sure that any head opening in children’s wear clears 18″. That’s been the ongoing standard for many of the companies I’ve dealt with in the past.

    My question is this… Are you aware of any standards imposed on companies by our government concerning minimum neck openings? Also in your experiences, what do you consider to be the minimum circumfrence for neck openings in childrens wear and adults?

    Thanks so much!
    Sincerely,
    Ellis

  7. Debra says:

    As a long time industry patternmaker and grader, grading manually 12 yrs and on Gerber CAD for 8 yrs, I agree that CAD is the only way to go for ALL of the reasons stated in the article answers above. Yes, I have had many, many grade rules on file to use when needed, some often,others not so often. And I do feel strongly that the patternmaker grading her own pattern is best.(In some companies they have patternmakers and then only people who grade, since patternmaking is much more technical)…as an example, I can “see” if my graded nest is not going to work in the largerst or smallest sizes. Of course when there is an actual miscalculation made sometimes the janitor could notice it! Or if you entered postive instead of the negative!
    You graders know what I mean, sometimes you have created an interesting contempory piece of linear and curvy artwork! Just plot it out on the plotter and hang it on the wall, and your friends won’t notice that is was a good shirt pattern gone bad! Ok…I’m getting tired and goofy….two more things, I have been given grade rules that I feel could be altered, and I as a patternmaker had the ability to make changes for the better. Now I do remember when learning to grade, and given a set of grade rules I could look at the figures and have no idea if a figure was out of sync, but sometimes once the pattern was graded, the out of sync measurement on a nest stuck out like a sore thumb. That was as a novice, now I can just usually look at the rules and see it, that comes with experience.
    Last but not least….to Kathleen…I think the information you are giving to us is extremely informative, I also understand it though too.
    Maybe the DE’s out there are finding they don’t understand it all although they are learning..
    they may NOT know what questions to ask…….yet..
    Clear as mud right?

  8. trish says:

    I am so glad F-I readers are enjoying the Apparel journals. I “pack-ratted” them for my own needs and for the future of our industry. I have years of Bobbin Magazine and Apparel Industry Magazine, so after Kathleen works her little heart out for us with these journals, we have to have her start on all my old mags (those were the days!!)

    On grading and grade rules: my college students have to do three levels of self-training on grading. Anyone who applies her/himself always learns how to grade.. and how to use the jumps from measurement charts to develop grade rules.

    I am not a lover of Delta grading and I wish that when the industry converted to CAD that someone would have been around to explain that Delta (x/y axis) grading was invented to save time over the older version (where one cut the pattern and exploded it out for larger sizes and condensed it down for smaller sizes.) Trust me, it is soooo much easier… never any confusion about positive and negative.. but, oh well, the computers have been made to think Delta for all the wrong reasons. CAD could have so easily used the older method, for although it was more time consuming by hand, it would be faster than Delta grading on the computer.

    If I may go on… when teaching my Computer Aided Apparel Design class, I write all kinds of errors into the grade rule tables that the students will use on several garments. Then when the grading is implemented (on the screen) you see all kinds of hideous mistakes… easy mistakes to make (neg vs pos; wrong values in the x and/or y; typographical errors — you know typing 224 when you meant to type 24, etc.) This seems to be a great way to teach so that students will know how to find and correct errors in grading at work, before it ends up on the cutting table.

    Kathleen, I would love to comment on more things but this is getting long to read and I am still here at work and it is 11:30 PM… I have been here without a break since 10:30 AM and I still have about two hours of work ahead of me… our fashion show is in 42 hours!!!!

  9. Esther says:

    Ellis, I just wrote a post on my blog about neck circumferences for infant/toddlers at Design Loft. It may be of some interest to you.

    I think networking with others in the business helps solve a lot of problems. ;)

  10. jinjer markley says:

    this is a totally fascinating subject–I can’t wait until I take grading in the Fall (God willing I’ll figure out a daycare situation). Which is to say, I don’t even have novice skills, but I’ve always wondered this:

    how are grade rules created? Did somebody at some point take a bunch of women of roughly the same figure type, but different sizes, and figure out how their well-fitting patterns differed? would there be any merit to doing this?

    When a grade rule looks wrong, how can you tell?

    Trish says:
    where one cut the pattern and exploded it out for larger sizes and condensed it down for smaller sizes.

    is this sort of like converting a bodice block to a jacket block?

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