You can make use of indirect valuation badi "HR_INDVAL" to define your logic. Ask your functional consultant to define an indirect valuation module and assign it to the overtime wage type in spro. Then you can write your logic in the implementation of badi "HR_INDVAL". You won't be required to carry out any calculation in your upload program or even when you create it through PA30 as overtime will be calculated using badi based on overtime hours and other parameters.
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