The gains made as the result of an improvement process can best be maintained by...

The correct answer is C. Modifying procedures to reflect the changes in the revised process . The CSSBB control-phase material states that the project control phase is necessary to sustain the project gains and that the control plan must remain a living document. It also lists specific closing-phase actions, including creating updated work instructions and procedures , training affected personnel, and ensuring the revised controls are embedded into the system.

This is a core sustainment principle in Six Sigma. If procedures and work instructions are not updated, people often drift back to the old way of working, and the improvement erodes over time. Aligning results with strategy and informing leaders are useful, but they do not by themselves lock the new process into daily operations. Budget adjustments also do not ensure standard execution. The most direct way to preserve the gains is to revise the formal procedures, standard work, and control documentation so the improved method becomes the new normal. Therefore, the best verified answer is C .