"Brenda's spreadsheet" has unreasonable staying power in organizations.
Imagine a load-bearing business process, currently supported by a single jury-rigged spreadsheet authored by Brenda.
Consultants are brought in to build The Sustainable Answer.
They interview everyone who relies on the process, and everyone tells them what they need.
The consultants build the process… and then everyone keeps on using Brenda's spreadsheet.
Why?
Brenda's spreadsheet has captured the unknown knowns… the parts of the process all of the experts can sense but no one can put into words.
Plus, a formal process doesn't provide a single neck to choke.