Mistakes are always tolerable but it should be recovered before the device or product come into real world. I personally feel ECO can alert the team members to be cautious about each and every step ahead. Once there is a change in the project due to some mistakes or lacks then the management seems it to be a serious issue and it will be taken into consideration. This allows the team members to discuss about the project changes and helps in preparation of the further more changes in the validation and verification. I do not have any industrial experience but I have faced changes in the research work, which leads to lot of impact on the entire data analysis. For instance a filter change in the signal processing may cause a major change in the results. So a keen watch of the development and changes in the measure should be seen.