An analysis may be represented as a feature in a feature-based model of a geometric object. The analysis is integrated directly into the model and may be recalculated in response to changes made to the model. Additional features may be created that reference the analysis feature. Likewise, the model may include features that reference the analysis without directly incorporating the analysis into the model as a feature. The analysis may be a system-defined analysis, a user defined analysis or an external analysis.

A computer program apparatus for analyzing design tolerances having a computer readable medium and computer program instructions. The computer program instructions are recorded on the computer readable medium and are executable by a processor. The computer program instructions are capable of performing the steps of facilitating the graphical identification by a user of a first and a second entity, identifying any objects related to the first and second entities, storing the identified dimensions and tolerances relating to the identified objects, and, analyzing the stored dimensions, to, in turn, determine the interfacing of the objects relative to each other.

A method for performing geometric dimension and tolerance stack-up analysis for an assembly, the method comprising receiving a target assembly dimension for stack-up analysis, where the assembly includes at least one part. The method further comprises receiving a feature corresponding to the part and receiving feature tolerance data associated with the feature. The feature tolerance data includes at least one of size tolerance and geometric tolerance. Stack-up rules are accessed in response to receiving the feature tolerance data. The stack-up rules include instructions to determine if a form tolerance, an orientation tolerance and a profile tolerance should be included in a stack-up tolerance for the feature. The stack-up rules also include formulas to calculate a nominal dimension and the stack-up tolerance for the feature when the feature tolerance data applies to features of sizes. The nominal dimension and the stack-up tolerance are derived in response to the stack-up rules and the feature tolerance data. Stack-up analysis is performed in response to the nominal dimension and the stack-up tolerance. Performing stack-up analysis results in a mean and standard deviation for the target assembly dimension.

A mechanical tolerance method which links mechanical assembly tolerancing requirements to part variation controls. The method optimizes tolerance for a design. The method begins by a user defining an assembly requirement. Next, datum features are defined. The method then moves to the step of assigning component dimensions. A dimensional loop diagram is generated for each component. Next, an appropriate analysis/allocation method for determining tolerances of the components is determined. Upon selecting the appropriate process, variation controls are applied to the plurality of components. Next, tolerances are assigned to features of the components.

Determining a minimum condition and a maximum condition of an assembly of parts includes determining a subset of the assembly of parts, constructing a tolerance chain comprised of tolerance features associated with the parts and that have tolerances that can assume maximum and minimum values, setting at least one tolerance to a minimum value or a maximum value, and calculating the minimum condition and the maximum condition of the assembly based on the setting of the tolerance.