When a customer reuses a software component, the obligation to reimburse the providers of the reusable component is totally dependent on the kinds of agreements binding the software project as well as copyright undertakings.
In cases where the provider of the reusable component is to be reimbursed, the payment mechanism has to be one that is agreed upon by both the provider and the customer. If the reusable components are well identified and compact, the provider can seek a percentage of the amount it's worth, each time the component is reused.
Again, this is not the only way to do this. The type of payment mechanism used will ultimately depend on the nature of software development agreement or contract.
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