Design Analysis

 

How to Determine Where to Spend Time Redesigning

Unless the part/component that you are designing is an NPI/NPD part or it has re-entered the design cycle due to a quality or performance issue, you must decide what is worth your time redesigning. For example, a re-design may be necessary because a part is over cost and has a large opportunity for future savings, or because a part is riddled with DFM issues that your supplier or manufacturing team need to accommodate. Removing such issues may reduce cost and provide a lower quality risk.

To identify the part you should work on, we have a few basic rules, and aPriori provides analysis tools to indicate what may be worth investigating.

Aside from the obvious “manufacturing is always asking for deviations on this part” (indication of DFM issues), or when it has been made clear to you that a part is driving the cost of the product disproportionately, we recommend that you start your selection process by asking the following questions:

  • Which parts that I am responsible for have a significant production forecast in future years AND the projected spend (Cost x Production Volume) is so significant that a potential reduction of 10% would be worth the redesign effort. Typically, this would equate to > $25,000 in savings.

  • Are there commercial/legal reasons that the component could not be manufactured using an alternative design? For example, would a redesign require a re-certification which would drive the implementation cost excessively high? If yes, eliminate those components/parts from the equation.

Gather The Data You Need

After you have the parts you want to analyze, you need to group them by process, cost and publish them in aP Design. To do that you will need the CAD file, 2D drawing, and approximate production volume.

Tip: Note: When costing use the same average batch size for all parts.

After you collect this data, segregate the parts by manufacturing process and material type; Sheet Metal Parts, Castings (including Machined Castings), Forgings, Injection Molding, etc. Secondly, segregate by material types – ABS, Nylons, PETs, and so on, or Steels, Ti, AL, and so on.

Create Projects in aP Workspace

Now you have identified groups of parts to analyze:

  1. Open aP Workspace and create a project containing each sub-group of parts. See how to Create a New Project in the Collaborate Using Projects section of the aP Workspace documentation.

  2. Add one of your colleagues with a license that includes access to aP Pro to the project. Request that the aP Pro user creates a rollup of the parts within aP Pro. This will allow for the export of the parts into aPriori Reporting application. For more details, see the Roll-ups, Dynamic Roll-ups, and Functional Groups section in the aP Pro User Guide.

  3. After the parts are uploaded into a rollup, the aP Pro user should comment on one of the scenarios within the project to let the design user know the task is complete. See Collaborate Using Messages and Comments for more information about comments in aP Workspace.

Export The Parts to Our Reporting System – aP Analytics

Now that you have costed the parts, and are ready to analyze, you need to export the roll-ups (data sets) to our Analysis Tool, aP Analytics. If you are not familiar with how to do that, see Managing Scenario Export and Purge in aP Admin.

Tip: You may need to request permission from your system administrator to allow you to export data to the reporting system.

Conduct The Analysis

There are several analyses you can run to investigate which parts may be worth your time to redesign. aPriori provides these analysis reports within the aP Analytics Library. Usage of the reports is dependent upon having exported your data set (roll-up).

Design outlier report or DTC for Design to Cost shows which parts are more expensive relative to their peers. This report is available for Machined, Sheet Metal, Casting, and Plastic parts and can be found in the section of aP Analytics called Reports.

  1. Click Reports to open the repository of reports in aP Analytics.

  2. Scroll down the list until you see the report that matches the process of your data set:

 

  1. This is your first report and provides a general feel for where the parts you have selected fall relative to each other in terms of cost and manufacturability, so we recommend running it first. See report below:

 

  1. Hovering over the circles shows you the part number and details of cost, annual spend, mass, and so on. Clicking on it shows you the part and details about the part cost. The color of the bubble indicates the number of DFM issues in that part relative to the others being analyzed.

 

In this example, based on these first results there are two parts to review:

 

  1. Click the Comparison link to get your second Report showing the DFM issues for this set of parts. Note that the issues will vary based on the manufacturing process. Here you can see the Machining issues. If these were plastic parts, you would see issues such as draft angles and thickness violations.

Next Steps

You can see from the results above that the part called MC_POCKET is consistently at the top. Another bubble, RING-3, appears to have a lot of slow operations on the top left chart. The third part worth exploring for redesign is AERO MILL BEFORE. It looks like this part has a lot of L/D ratio type of DFM issues.

So, of the 12 parts, only 3 are worth exploring.