$10 is for the one you lost and another $10 for one you are going to buy again. "Therefore take care of your essentials and count the invisible loss", she said.

That's the early learning I received when I was young and revalidated it during lean six sigma lessons. This is not something new that has not been told in generation or adopted by dubbawalas and later theorized during industrial revolution, however in general it is still not practiced as efficiently as it should have been.

That's the basic principle applicable for any supply chain as well as in software industry. It is as essential as our lunch box, to avoid any loss happening due to wastes in processes, man power utilization, lack of re-usable components, not using accelerator tools (software), utility or even loss of a piece as small as a nut which part of supply chain/delivery/assembly line. Those losses costs a company more than the cost of that lost element itself.

That's where dependability and survivability measurement kicks in. The more dependable supply chain element is, higher survivability should be worked out to avoid loss/failure/errors.