As industrial engineers, or any kind of engineer for that matter, were held to a higher standard than others in the workplace that might be taught to use Six Sigma tools. You've seen in your readings that many organizations create process models - primarily SIPOC and PMAP diagrams - that lack rigor when aspects of those diagrams are coordinated across a set of models.

In particular, we've focused in this class on making sure that inputs and outputs are always balanced and conserved across sets of models. The inputs in the SIPOC are the only allowable initial inputs into the High-Level PMAP steps (along with other work-in process inputs that can be described using outputs from other PMAP steps. The inputs to each High-Level PMAP step are the only allowable initial inputs into the Detailed PMAP for that step (along with other work-in-process inputs that can be described using outputs from other PMAP steps). The outputs from each High-Level PMAP step are the allowable outputs in the steps of the Detailed PMAP (along with other outputs that are consumed within that Detailed PMAP as work-in-process). Finally, the outputs from the SIPOC are the allowable outputs from steps of the High-Level PMAP (along with other outputs that are consumed within the High-Level PMAP as work-in-process). Ultimately, the SIPOC outputs are derived from nothing but the SIPOC inputs and all SIPOC inputs can be shown to be needed to produce those SIPOC outputs. We use different adjectives in the naming of these inputs and outputs to show variation in their processing states, but otherwise we try to maintain complete conservation of inputs to outputs.

The books and articles we read about Six Sigma methods and tools almost never discuss these models with this level of rigor. This is because Six Sigma is a populist approach; training being given to everyone in a company across all categories of positions. Engineering rigor isn't expected when drawing these models among such a wide array of people having such a wide array of skills and capabilities. As engineers, we can hold ourselves to a more rigorous standard, and the assignments in this class do so,

Discuss some of the things that can go wrong on a Six Sigma project that doesn't practice the level of conservation rigor required in this class. What different problems or outcomes might be expected, and how might these affect Six Sigma projects done by teams in organizations? To what extent might it help for all Green Belt project teams to have access to a Black Belt to assist them?