Explicit variants are one of two ways of representing variants in OptiLine, the other being the implicit variant representation by means of a BOM (Bill Of Materials) with possible product models.

    With explicit variants, each of the possible variants of the product being assembled on the line is explicitly listed, together with all operations being present for each of the variants. One of advantages of explicit variants is that it is possible to know exactly what are the possible combinations of operations for any variant. That makes it possible to compute workstation peak times and take them into account in the automatic balancing optimization. A workstation peak time is the time it takes to complete all the operations assigned to a workstation, whatever the variant being assembled at the station.
    A disadvantage of explicit variants is that when there are many different variants, entering the data may become cumbersome. Such a situation may arise in cases where instead of a series of different product models with fixed sets of options, a number of options are available independently of each other. Also, OptiLine is currently limited to a maximum of 1000 explicit variants. For cases where explicit variants are unworkable, OptiLine offers the implicit BOM variant model.

    Explicit variants are easily visualized in the Operations Tab in variant mode, activated by the Variant navigator. For instance, showing the fuel model of the car would yield the following figure, where the "Mount Diesel Engine" operation is struck out, because that operation is absent from that variant (it only appears in the fuel model).
    Since some operations are present and others are absent in a variant, the execution time on workstations varies from one variant to another. This is conveniently represented in variant mode in the Workstation tab.