Sales plan & demand planning

The short answer

Demand planning captures how much of each product you expect to need — as a forecast, from confirmed orders, or both — and turns it into the sales plan that seeds every MRP run. It is the front door of production planning: nothing downstream can be right if the demand it starts from is wrong. The sales plan states gross demand for finished goods over a horizon; MRP then explodes that demand through the bill of materials and nets it against stock. Get the demand plan right and the whole chain — explosion, netting, purchasing, scheduling — inherits a sound starting point.

This guide sits under the pillar, what is production planning software?, and leads into how MRP works, which consumes the plan this one produces. The product page is Sales & production plan.

What demand planning is

Demand planning is the discipline of deciding, ahead of time, how much of each finished good you will need and when. That decision can be a prediction or a fact — a forecast of what the market will take, or a set of confirmed orders already in hand — but either way it produces a sales plan: gross demand for finished goods, product by product, period by period, across the planning horizon.

It matters because MRP is a downstream calculation on this input. The explosion multiplies the demand down the BOM; the netting subtracts stock from it; the schedule sequences the work it creates. Every one of those steps is only as good as the demand it started from — which is why demand planning, unglamorous as it is, is the highest-leverage number in the whole plan.

Forecast versus order-driven demand

Demand arrives in two forms, and they map onto the two manufacturing strategies covered in make-to-order vs make-to-stock:

Most plants plan both at once: a forecast for standard, stocked products and confirmed orders for configured or high-value ones. A capable demand plan holds them together, so the same run nets the forecast against stock and pegs the orders to their customers.

Sales plan and production plan

Two related plans sit at the front of MRP, and it helps to keep them distinct. The sales plan states demand — what the market is expected to take. The production plan states supply — what the factory intends to make to meet that demand, once you have adjusted for stock on hand and decided how to level output across the horizon.

Levelling matters because raw demand is lumpy and capacity is not. A production plan that smooths a demand spike across the weeks before it keeps machine loading under control, rather than handing the scheduler an impossible week. The demand plan is where that shaping begins.

Basic forecasting methods

Where demand is a forecast, a few standard methods turn history into a prediction:

• Moving average — average the last few periods to smooth noise. Simple and stable, but slow to react to a real change.
• Exponential smoothing — weight recent periods more heavily than old ones, so the forecast follows genuine shifts faster.
• Trend and seasonal methods — add a slope for growth or decline and a repeating seasonal pattern for predictable peaks.
• Judgement overlay — the sales team's knowledge of a big tender, a new customer or a festival build-up that history cannot see.

The point is not a perfect forecast — there is no such thing — but a good-enough demand plan that MRP can net against and that is revised as real orders arrive. A forecast that is reviewed and corrected every cycle beats a sophisticated model that is set once and trusted forever.

How the plan seeds MRP

The sales plan is the gross demand MRP begins from. For each finished good in the plan, the MRP engine explodes the demand through the bill of materials to gross requirements for every component and material, then nets those against stock on hand and open supply to get net requirements — which become purchase requisitions to buy and work orders to make. Because netting is against current inventory, the plan is a with-stock calculation: the same demand produces fewer orders when stock is high and more when it is low. The full mechanics are in how MRP works.

Why demand accuracy propagates

Because MRP is multiplication down a tree, an error in the demand plan does not stay small — it explodes. Overstate demand for one finished good by 20% and you overstate the requirement for every component and material beneath it by 20%, ordering material you will not use and loading machines for work that will not sell. Understate it and you stock out across the whole structure. This amplification is why demand planning deserves more care than any single item parameter: it is the one number every other number is derived from. It is also why the demand plan is revised continuously rather than set once — each cycle folds in the orders that have actually landed, tightening the forecast as the horizon approaches.

Seasonal and festival demand in India

Indian demand is strongly seasonal, and predictably so — Diwali, the wedding season, harvest cycles and monsoon-linked patterns drive large swings that repeat every year. A flat demand plan built on an annual average will always be wrong in both directions: short before the peak, long after it. The discipline is to build the seasonal shape into the plan, raising the sales plan for the pre-festival build-up so MRP orders material and schedules production early enough to have stock ready when demand arrives, and lifting reorder points so buffers grow in advance. A plant that plans the peak ships it; a plant that reacts to it stocks out during the exact weeks that matter most. Seasonal shaping in the demand plan is one of the clearest advantages a planning system has over a flat spreadsheet.

How Fast Planning captures demand

Fast Planning Software — built by Improsys in Pune under the Fast Technology brand, cloud or on-premise — captures demand in the sales / production plan for a horizon, typed against a forecast for make-to-stock products or pulled from confirmed orders for make-to-order ones, or both in one plan. That plan seeds the MRP run: each finished good is exploded through its BOM and netted with-stock against live inventory to produce purchase requisitions and work orders, which are then loaded onto finite machine capacity and sequenced on the Gantt board. Planners shape the plan for seasonal peaks ahead of time, and because it runs on the shared Fast Suite database, the demand a planner enters flows straight through explosion, netting, purchasing and scheduling with no re-keying — one plan from demand to shop floor.

Frequently asked questions