The basis for (molded) part development, mold design and manufacturing are the service or application conditions (AC) of the (molded) part. If dimensional changes occurring over time after manufacturing are relevant to the function of the parts, these must be taken into account when defining the dimensional position, dimensional shift and dimensional scatter.


Starting from application-related or functional requirements for dimensions, tolerances and fits, the values must be transformed to the respective other dimensional reference level.


The following two dimensional reference levels are distinguished:


    • Fabrication acceptance conditions (FAC)
    • Application conditions (AC)


The dimensional reference levels are defined as follows:


    • AC: Application conditions (all operating and storage conditions during the period of use and after manufacturing, insofar as they influence dimensional stability and functional performance)
    • FAC: Fabrication acceptance conditions of (molded)part production (when molded parts are stored after manufacturing until acceptance at 23 °C ± 2 K and 50 % ± 10 % relative humidity, and are inspected no earlier than 16 hours and no later than 72 hours after production)


f, for example, the dimensions are available under the fabrication acceptance conditions (FAC) or have been calculated accordingly, they can additionally be evaluated for plastic molded parts using DIN ISO 20457 (also included in this software). This means assessing whether, how, and under which conditions the dimensions, tolerances and fits under FAC can be realized. This may also lead to the need to refine previously made decisions regarding the (molded)part material and/or the supplied components. In turn, this may require corrections or refinements to the mold design. Consequently, this is generally an iterative process.


The definition of application conditions (AC) and the resulting material-dependent dimensional changes, if applicable, form the basis for the calculation and transformation to the respective other dimensional reference level. 


Dimensional changes (i.e., previously defined ACs) can be assigned to:


    • the (molded)part,
    • the respective fit reference part, and/or
    • individual dimensions (e.g., for wear, expansion, or compression).


The functions of the software are not limited to plastic parts. In practice, plastic parts are often used in combination with components made from other materials (e.g., in fits or with inserts). Therefore, the software can also be used without restriction for components made of other materials.