Hi, You can even think of reorganising your purchase procedure for optimization. But you need to be more careful while doing because the cp and cpk might conflict with the outcome, ie you may have excellent results but the project potential might not be healthy and this might even lead you to the project rejection. Please check the cp and cpk before you proceed with the project. If the cp and cpk are not at the desired levels, then you would be doing just a Kaizen and not six sigma. Purchase is a very vast area and every activity has a potential for improvement. You might get plenty of opportunities for doing a six sigma project and improve the level of operation. Please do not hesitate to write back for any further clarification. Thanks and regds Priya