Since it is known that going back to a previous phase during the review meetings can be really expensive and counterproductive, I was wondering about the amount of error and deviance from the expectations that must occur for something like that to happen. Of course, I recognise that this depends on each product and case but was wondering whether there is some consensus on that.
I feel as though going back to a previous phase is not counterproductive as long as the issue(s) are resolved, or a better proposition is put forth. It could cost financially, however for the progression of the project and to continue to the next phase, it is important to ensure that previous steps are not left unfinished. There is no numerical value of how much error or deviance would occur from the expectations to have counterproductivity. I believe that the severity of the issue from the previous phase determines how quickly it can be resolved and pushed along, which would impact the timeline and financial side of the project. Having mistakes is not bad, as long as it does not shake up the projects trajectory too much.
There would have to be something fundamentally wrong with the project in order to go back to a previous phase. The design review process is set up to guide the project forward. Certain requirements must be met to move on to the next phase. A common phase for the project to hit setbacks would be V&V. If the project is consistently failing V&V test, the project might get kicked back to development to work on the issue.
Once a product is in post-release phase, it may also go back to previous phases. For example, if a product is receiving complaints in the market, a new design project may be initiated to fix these issues. Sometimes all of the design phases are completed again,
