I have a feeling that the cost of bad / inefficient / late software runs into at least the billions. The biggest risks are unavoidably attached to the most cost

I have a feeling that the cost of bad / inefficient / late software runs into at least the billions. The biggest risks are unavoidably attached to the most costly software projects, that are probably the most likely to be conducted in the most sophisticated and professional fashion with the latest silver bullet methodologies. The Mythical Man Month is just over half a century old, yet still reads like it was written yesterday.