More than one modules implementing the hook_module_implements_alter How can I know what module will implement earlier?

I have a module (custom) which implements hook_module_implements_alter and an other module (contrib) which is also implements it. In this case the contrib module is being executed later, overriding my implementation.

So, how can I ensure that my module will be executed later?
You need to change the weight of the modules in system table to modify their execution order.

One module that can help you in that is the Modules Weight, which provides an admin interface and avoids changing the SQL record directly.