Effy's pissed.
Efficiency is defined by the amount of outputs a process is able to generate, out of all the resources it uses. The easiest example would be financial efficiency, as all inflows and outflows can be measured with a common unit: money. That'd make: financial efficiency = amount of money generated (flowing out) / amount of money invested (flowing in). Quite straightforward, anything over 100% would be efficient, and anything below would be inefficient, with the gap being... wasted.
Applied in general fields, wastes result from inefficiencies, though not necessarily financial ones. For example. a sale staff from a Shanghai luxury shop might be wasting his time during coronavirus as time will never be gained back. However by selling two bags in one day, the process itself might still be financially efficient for the shop owner as the price will be enough to cover the good, the sale staff salary for the day, the rent, utilities, etc..
Unfortunately, not all wastes generated from financially efficient processes are as benign as the cashier's waste of time. On the contrary, some wastes have very high toxicity, making it easier now to understand why Earth looks a bit feverish.
Since financial efficiency seems to be the main scale used to assess a process overall efficiency, a better grasp of wastes toxicity in the model is becoming urgent. One way would be to increase the negative value of these toxic outputs, another would be to consider the curing cost as monetary inflows (for example imposing the provision for waste treatment and asset closure in financial accounts).