For your business to effectively carry out the supply chain planning process, you will need to link up your short-term and medium-term, to the executive level S&OP plan so that it drives your tactical planning and operational planning.
Some time ago, I had been trying to help a business improve its statistical forecasting. We tried different parameters and different forecasting algorithms but the statistical forecast for about half of the products could not be improved no matter what we tried. We decided to do a deep dive to understand the reason.
With strong leadership by the executive team, over time, the business begins to think in terms of overall health and welfare of the company, rather than optimizing a function at the expense of the overall company benefits.