SWAG or Consensus Guess are purely avoidable as this is the base for running a LEAN SIX SIGMA concept. MSA is the tool to assess the potential risk and Highlight the same to all Stake Holders on the Decision's impact which is based on the Consensus Guess.
Example can be as Below;
Management thinks that introducing a WMS will increase Productivity in Warehousing Operations - This is Guess
A MSA is run and following Outcome are found;
The Cost of Implementation is soo much that it will Impact COGS
Implementing WMS will attract Opex Cost for which Business is not ready at this moment
Trained and skilled workers are required to operate the automation
It has a potentiality to Slow the Operations Speed in high Peak Season due to non availability of Resource or Infrastructure
Later it was found that requirement is to categorise the Warehouse, Concept wise and each shipment whether In or Out needs to be traceable.
The above example is a clear case where implementing WMS looks a better option from Management or a Decision makers group's perse but After a MSA the potential risk got highlighted and while use of DMADV the new process came into existence