Transformations in a mapplet can be reusable or non-reusable. If you add a Sequence Generator transformation to a mapplet, it must be reusable.

When you use a mapplet in a mapping, you use an instance of the mapplet. Any change made to the mapplet is inherited by all instances of the mapplet.

Mapplets can contain other mapplets. You can also use a mapplet more than once in a mapping or mapplet. You cannot have circular nesting of mapplets. For example, if mapplet A contains mapplet B, mapplet B cannot contain mapplet A.

For example, the following figure shows a mapplet that combines customer information from east, west, and central regions with the help of a Union transformation:

The following figure shows a mapping where you can reuse the customer mapplet and find the customer who bought the maximum items in each state:

You can create a mapplet manually. You can also generate a mapplet from a segment within a mapping or mapplet.