Your organisation should have a bias towards continual improvement, so you not only improve what you do but do so whilst using less resources. This not only reduces cost (and improves profit margins) it's also a matter of survival in a world of finite resources.
Therefore, aim for transparency of costs by using Maps to see how you create value for customers. Challenge what is being built to ensure you're focused on meeting user needs and not 're-inventing the wheel' or custom-building toasters. You should also have a clear system of measurement for assessing whether what you do is adding value to all stakeholders.
Remember, this is an iterative process — doing better with less requires navigating a constant cycle of learning and improvements over time. So the sooner you start the better.