ObjectGears

(Translated from another language)
There is Valid to property in the Service contract and there is again Valid to property in the CI support. Isn`t that duplicity. I find it complicated. I think I can define list of supported configuration items in the service contract directly.

Valid to in the Service contract relates to the Service contract itself. This contract may cover more configuration items (CI) with various support type and various support period. If e.g. the Service contract is signed for one year with validity till 31.12.2016, but you plan to remove some configuration items till 31.7.2016, than the support is ussualy prepaid only till that time. This is why the end date is recorded also in the entity CI support.
If you do not want to distinguish various support types and various end of support for configuration items in a single contract, you can record it directly in the Service contract entity. You will simply create multiple reference column refering to the CI class in the Service contract class.