Production planning is a complex process that covers a wide range of activities that insures that material, capacity and human resources are available when needed. If I had to choose one definition for production planning I think Yogi Berra said it best "if you don't know where you are going, you might not get there", or more accurately, you probably won't get there. The only way to effectively know where you are going is to have a good process to generate a production plan or production scheduling document.
The production planning document typically starts with a sales forecast, or sales plan usually supplied by the marketing group. From the production planning document all other process's start. The production planning document can include material, labor, capacity, training and should include a backup plan should things go wrong. Each area of planning is dependent on the other and must be done in unison. It makes no sense to bring in material if production can't produce, or plan production if materials are not available. It requires a collaborative effort between different departments to effectively bring all aspects of the process together.
