There are two major categories in this area:

The main issue in Tolerance Analysis is how to calculate the total variation from accumulating tolerances. Therefore, tolerancing and tolerance analysis are integral parts of the engineering process and product lifecycle management in order to produce high-quality products at reasonable prices. This costs time, money and increases the weight of the aircraft, reducing its fuel efficiency. Aircraft wings may need large amounts of shims if the tolerances are incorrect in order to fit properly to the fuselage. An automobile door will not close well if the tolerances are very large, and may have additional road noise from a poor seal. In the same regard, the performance of a part and product is influenced by tolerances. The tighter, as in the smaller, the tolerance, the more difficult the part is to produce, and the more expensive the part is. The same applies for plastics, composites and any given part. A piece of sheet metal that is quickly stamped using a stamping die is much cheaper to produce than one that needs to be machined to more precise dimensions.

Tolerancing directly influences the cost and performance of a product. Tolerances Directly Affect Production Costs This variation is captured in design as tolerances, depicting the range of variation acceptable in the design. Due to variation caused by material characteristics and manufacturing processes, such as stamping and machining, parts are always made larger or smaller than their nominal design. When manufactured, parts are never made to perfect specifications. What's more, those tolerances and variation can greatly affect production costs. It is important to account for manufacturing variation, as there is no such thing as perfect parts.

3D Stack Analysis – CAD Tool (3DCS falls into this category).

2D Stack Analysis – Excel Spreadsheet or Software Tool.

1D stacks do a single directional linear stack, while 2D stacks and 3D stacks include multiple directions and influencers.Īs we discussed in our article, What is Tolerance Analysis?, there are really four different methods of doing Stack Analysis. Tolerance Stacks calculate the accumulated variation across a set of dimensions. Traditional methods of tolerance analysis include 1D, 2D and 3D Tolerance Stacks, and statistical methods like Monte Carlo simulations. Tolerances are determined by a variety of methods, from standards such as ISO or ASME, or from the use of geometric dimensioning and tolerancing (GD&T), a method of annotating and marking tolerances on parts. It is often applied to manufactured parts in general to determine the impact of manufacturing processes on the final dimensions of those parts. What Is a Tolerance Stack-Up? How Do You Calculate It? Tolerance Analysis encompasses several processes used to determine the potential accumulated variation in manufactured parts and assemblies.

Tolerance stack up