A design test on data collection (i.e. check sheets, control charts, etc.) can be used to evaluate the effectiveness of the actions. The process can be monitored using control charts and histograms. An action plan should define who, what and when clearly to coordinate the interim fixes.
Individuals should be encouraged to gain knowledge about the entire process. Ask - What would be the effect of:
Incorporating robust engineering designs
Establishing manufacturing feasibility
Determining how one operation or dimension affects another
Centering the process
Over adjusting and / or under adjusting a machine or process
Improving machine set-up
Improving maintenance, etc.
Well engineered management systems, practices and procedures need to be coupled with effective training programs. Together these can provide the best protection to prevent recurrence of the problem by new technologies, new methods, new employees, job rotation or improvement of individual skills.