Tolerance Stack Analysis

Don't tighten that tolerance, fix the cause instead!
Our Tolerance Stack Analysis simulates manufacturing and assembly to:
  • Ensure components fit together -- from concept to production.
  • Fix in-production systems with quality issues -- we find and solve root causes like no one else can.
We accurately and quantitatively predict fit-up yields, sigma values, and other quantitative measurements of quality, starting with as little as concept sketches or as much as complete prints and production data.

Prairiefire’s system sensitivity approach allows us to quickly find the effects of design or tolerances changes. Our experience with design solutions makes fit-up part of your design rather than something that happens after engineering and during production.

Our solutions are less susceptible to manufacturing variation, less expensive, and more sustainable than tightening tolerances everywhere there’s a problem. When you tighten tolerances, every part you make costs more. Instead, investing in a Prairiefire design solution saves you money on every part because tolerances don’t matter as much in the first place.

If you’re chasing a fit-up issue by tightening tolerances, let Prairiefire find the root cause of your problem instead -- we deliver faster, less expensive, more sustainable fixes.

Inputs to the Analysis

It sounds clichéd, but the most important input for solving your problem is Prairiefire’s years of experience applying Sensitivity-Based Design -- asking the right questions and applying the results.

We combine data from across your company to simulate your concept, per print, or as manufactured systems:
  • CAD geometry and even sketched concepts
  • Engineering print tolerances, including GD&T
  • Manufacturing and assembly methods, including fixture geometry
  • Inspection data, including 6 Sigma and other statistical measurements
  • Structural, dynamic, and thermal analysis results
  • Functional requirements and performance goals

Results from the Analysis

Our analyses give you a complete picture of quality: not only how likely a part is to fit, but also the quantitative effect of specific parts, features, dimensions, and processes.

One of the most useful results is a quantitative map of sensitivities and contributions. This map shows how much of an effect each feature has, as well as why it has that effect.

Our results can include:
  • Fit-up yields, sigma values, lifespan, and other quantitative measurements of quality
  • Are tolerances tighter than required?
  • Do prints, tolerances, and datum schemes achieve design intent?
  • Design, fixture, and process qualification
  • Will deviated parts work?

Design Solutions

Prairiefire’s design experience, combined with our clear map of the design space, allows us to create functional solutions which are insensitive to variation.

On the manufacturing side, our results are a powerful and efficient troubleshooting tool. The sensitivities and contributions allow us to quickly identify and address root causes.

We work with your engineers, manufacturers, and suppliers, combining their knowledge and experience with our own to find the most economical fix.

To learn more about the tools we use, please see our list of tools.

What to Expect

After initially talking over the project with your engineers, we generally set up a site visit for the engineering and production facility. A site visit consistently saves several days of work for all of us by ensuring everyone is on the same page. Sometimes it even allows us to solve the problem on the spot.

We’ll agree on a scope and a quote and get to work.

A typical analysis project takes 2-6 calendar weeks from start to finish with final presentation of design solutions. We work hard to make our preliminary results available as soon as possible. That may be as fast as pointing out a quick fix when we first discuss the project.

We typically quote costs for analysis work on a per project basis.

Bottom Line

Whatever your group might call it (geometric stackup, tolerance stackup, tolerance analysis, dimensional management, dimensional engineering, dimensional variation analysis, statistical tolerance analysis, or root sum squares analysis), Prairiefire's Tolerance Stack Analysis gives you a complete and quantitative understanding of your system’s quality, down to the part, feature, dimension, or process level. We find how likely a part is to fit, and also why.

Our design solutions fix your problem, sustainably and without the cost of tightening tolerances.

If you are interested in going beyond consistent fit-up, we also offer Performance Analysis.
"Quite professional with their interactions and targeting needs and solutions. Interacted with Senior and newer engineers equally well as the shop floor in a remote location. We are looking to work with them in the future to bring more of their capability to our staff through engineering training they offer."

--Kezhun Li, Manager of Engineering Analysis at Case New Holland

Inputs come from all over.
Sensitivities and contributions allow us to
clearly and quantitatively identify root causes.
Quality doesn't just happen during
manufacturing, it's designed.
Extensive experience & flexible tools.