Best Sheet Metal Nesting Process Questions | CAD to CAM | Part 2 of 4

How to Evaluate the Nesting Process

Steps to Evaluate the Nesting Process

In the last blog post we laid out an architecture by which we can critically evaluate a nesting process.  To review, our evaluation process starts with a clear and detailed description of the nesting process, they we ask “why” about each of those defined steps, finally we look for constructive alternatives. Our goals in sum are identifying challenges, means to improve the process, and overall opportunities for efficiencies.

Today we’ll apply our evaluation architecture or system to the processes we’re most familiar with in nesting – collection of part geometry and creation of the part program.

We start at the beginning of the nesting process for most manufacturers, which is creating, identifying, moving, cleaning, and all around getting the geometry from where it is to a place – literally and figuratively – where it can be manufactured. 

Collection or creation of part geometry

This is the process of converting and migrating CAD work product to the CAM department for production.  What does that process look like in your operation?

Describe the CAD to CAM process

  • Look at all aspects of the process – who is involved, where are the decision points, what’s the information path, what is the timeline, what are the expectations?
  • Are the parts supplied by the customer? Created in house?
  • How are the parts created? Is each  unique or are they parametric modifications of a standard shape?
  • Are all the designs able to be manufactured? (angles, tolerances, reliefs, spacing, part sizes)
  • Are the CAD designs in 3D model form?  How are they unfolded?
  • Are the formed features, i.e. bend reliefs, able to be manufactured?
  • Do you use one CAD package or multiple? If multiple, is one appended to (same brand) the CAM package and used as a port of entry forCAM?
  • Are there legacy CAD files in an old CAD software proprietary format?
  • Are there part revisions? How are they managed and who has the authority to make changes? When can changes be made in design and/or on the floor?
  • Does the artwork ever need cleaning? Who is responsible for design or design editing?
  • How is data transferred and with what expectations for design quality and integrity of the recipient and the sender?  What decisions are made about the geometry and by whom?
  • Where are the manufacturing directives – leads, tooling, grain direction, common cutting – set and stored?

Evaluate the CAD to CAM process

Now break down the above described process and question – really look hard – at each point.  Why are things done as they are?  What bottlenecks or lag time is created? Who is inappropriately in or out of the information loop?

  • Are there redundant efforts – two sequential CAD packages, or cleaning geometry in two places?  Why or why not is this the case?
  • How well is revision management working?  Does it create manufacturing errors – wrong part, wrong quantity, wrong material?
  • How are the lines of communication working between CAD & CAM departments working?  Is there room for improvement?
  • Is there confusion among the stakeholders about who is responsible for what and when?
  • How long does it take to bring in clean geometry to the sheet metal software? Is that acceptable?
  • Are the manufacturing directives communicated clearly?  How’s that working?

Evaluate CAD to CAM alternatives

In step #2 above, we cracked open a whole bunch of issues that may signal some red flags for change.  Triage the above list creating a list of priorities – items that could be changed now, later.  Then look at alternatives.

  • What changes could be made to improve this situation?
  • How could it be changed?
  • Would that change involve process or policy changes?
  • What’s the upside of change? Can efficiencies in time or materials be gained?
  • Would training or retraining be helpful?
  • Is new technology warranted? Is there an opportunity to automate the process?  Is there an opportunity to integrate systems?
  • What would be the expected result of the change?  How would you know it worked?

Step two is simply a matter of repeating the same process as applied above to the next step in the nesting process – part programming.

Creation of the part program

Once the CAD file is cleaned and ready to go to production it still needs to be converted or programmed for nesting.  The nesting software needs to convert the graphical lines and arcs of a CAD file to the bits of programming code needed to nest and create a tool path.

Describe the part programming process

  • Are the parts programmed – in advance of arriving at the machine tool?  (Sometimes parts are programmed at the machine controller.)
  • How are parts programmed? What are the steps?
  • Is this done manually or automatically? Is there software involved?
  • Are the parts programmed one large at a time (single part programming)?  Per order? Per material? As needed? In batches?
  • How do parts get tooled (punch applications)?
  • How are leads added or not (contour applications)?
  • How are cutting techniques (common cutting, grain constraint, etc.) ascribed to the part?
  • Are they programmed for one machine or one cutting process?
  • Where are the part programs stored? Who has access?
  • What happens if there are revisions after a part is programmed? Who has the authority to make changes?

Evaluate the part programming process

  • Why are the parts programmed as they are (one at a time, batch, etc.)?
  • Are their particular programming challenges, i.e. beveling, that cause a problem?
  • Are there efficiencies that could be had, i.e. common cutting, that aren’t taken advantage of because of the programming challenge?
  • How long does the programming take? Is there a time-related opportunity cost?  Could resources be better spent elsewhere?
  • What is the chance of error in creating a part program?  Does that chance for error create a problem?  Is it a significant problem? How is the problem resolved now?
  • How does the programming process impact the nesting strategy?  Does it create or limit options?

Evaluate part programming alternatives

  •  In a perfect world, what would be the process?
  •  Does that “perfect world” imply less time spent, fewer errors, better communication?
  •  What solutions might aid in achieving that goal?
  •  Could programming automation make a difference?
  •  Could better integration with your CAD system help?
  •  How could this process be improved?
  •  Are there processes or policy changes that could relieve structural strain?

Now armed with an arsenal of good, probing questions, you can start reviewing your own process.  You may be surprised in what you’ll find.  You may not realize all of the steps in a process, understand the impact those steps may have on results or other processes, or know why it’s done this way.  You’re not alone.  As mentioned before, most manufacturers don’t take the time to look at the processes in this manner, so these helpful surprises are never uncovred.  However, when you do – and make the changes for the better – you will stand among the select few truly efficient manufacturers with insight into their process.

If you’d like some help reviewing your processes or if you think applying truly efficient part programming and nesting automation software may be a tool for you, contact Optimation.  We’d be glad to help.

In the meantime, what’s working for you?  What’s not?  Let us know and start the conversation on better management of nesting processes.

Notice: This work is licensed under a BY-NC-SA. Permalink: Best Sheet Metal Nesting Process Questions | CAD to CAM | Part 2 of 4

2 comments on “Best Sheet Metal Nesting Process Questions | CAD to CAM | Part 2 of 4

  1. Pingback: How well is your part ordering system working? | Optimation Nesting Software Blog

  2. Pingback: Evaluating the Sheet Metal Nesting Process | Part 4 of 4 | Optimation Nesting Software Blog

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