In Production Planning, Purchase Plan, Procurement Plan Projection is the base of everything for any manufacturing unit. If we do not predict our future, then we will not able to plan for it. A sales projection is the amount of revenue a company expects to earn at some point in the future. It's a prediction that is synonymous with a sales forecast. Both help determine the health of a company and whether sales will trend upward or downward. Small companies use various input to determine sales projections.