How Projected Balance Drives a Purchase Decision

Projected available balance drives a purchase decision by showing, bucket by bucket, the stock a part will have after netting future demand against incoming supply, so you buy when the projection first sets the balance to breach a reorder point or safety level, not when today's shelf looks low. In EDGEBIC by User Solutions that netted balance is the number every purchase decision reads from, because a purchase is about the future and the projection is the only forward-looking view of it. This post walks how to read the balance, spot the first breach, and turn a suggestion into a committed order.

The projected balance sits at the center of the replenishment loop. For the full picture of demand, buffers, and suggestions, read forecasting and replenishment explained, and for the balance concept in depth, see the projected available balance explained. Inventory features vary by installation, so check which planning capabilities your build exposes.

Why the Purchase Decision Reads the Future, Not the Present

A purchase decision is inherently about the future. You are committing stock that arrives after a lead time, to cover demand that has not happened yet. Today's on-hand tells you where you stand now, but it says nothing about whether you will be short in three weeks. That is why the decision reads the projected balance rather than the current quantity.

The projected available balance is what a part is expected to have in each planning bucket after the plan is netted: forecast and firm demand pull the balance down, and incoming supply pushes it back up. Run that netting forward across the horizon and you get a balance for every bucket, a trajectory rather than a snapshot. The purchase decision lives in that trajectory: the question is not "am I low today" but "where does the plan first take me below the line."

Because the balance is forward-looking, a part with a healthy shelf today can still project a breach several buckets out once demand is netted forward. Buying at that first projected breach, timed so the order arrives before it, is what keeps the reorder ahead of the lead time. Buying only when the shelf looks empty puts every order a lead time behind where it needed to be.

Reading the Balance Across Buckets

The projection lays the balance out one planning bucket at a time, on the inventory calendar and the matrix. Read it left to right and you are reading the plan's future.

Two lines matter as you scan. The reorder point is the level that fires a restock; the safety level is the buffer you protect against variability. As the balance falls across buckets, the first one that drops to the reorder point is the trigger, and any bucket that falls below the safety level is flagged below-safety and painted red. The headline metrics summarize this: the projected stockout metric names the first bucket that breaches the buffer, and the below-safety count tells you how many buckets are exposed across the horizon.

The reorder point and the safety buffer play different roles here. Safety stock, which absorbs demand variability, is the line you do not want to cross; the reorder point sits above it so a suggestion fires while the buffer is still whole. Reading the balance is really reading how close each future bucket sits to those two lines.

From Balance to Suggestion to Order

When the projected balance falls to the reorder point in a bucket, a replenishment suggestion is generated. The suggestion carries a size and a timing chosen to bring the balance back above the buffer before it runs out. It is a proposal, not a commitment: nothing has been ordered yet.

The purchase decision is what you do with that proposal. You review it against the projection, confirm the timing covers the breach, adjust the quantity if a pack size or minimum buy says so, and then firm it into a real purchase or work order. Firming it is the commitment. Once firmed, the order shows as incoming supply, and the netting adds it to the projected balance from its arrival bucket forward, so the red buckets after the arrival clear. Walk that step in how to firm a replenishment suggestion into an order.

That handoff, suggestion to firmed order, is where a proposal becomes supply. Until you firm it, the projection still shows the breach, because a suggestion is advice and only a committed order changes the balance.

A Worked Example: Buying Ahead of a Week-6 Breach

Take a purchased casting. On-hand today is 400. Forecast demand is 60 a week, the reorder point is 180, safety stock is 120, and the supplier lead time is three weeks. On-hand looks comfortable, so the instinct is to do nothing.

Read the projection instead. Netting 60 a week against no incoming supply walks the balance down: week 1 lands at 340, week 2 at 280, week 3 at 220, week 4 at 160. Week 4 is the first bucket at or below the 180 reorder point, and week 6 would sit at 40, below the 120 safety level and painted red. The projected stockout metric names week 6 as the first buffer breach.

The purchase decision is now concrete. A suggestion fires at week 4's trigger, sized to lift the balance back above the buffer. But the lead time is three weeks, so to have stock in place before week 6 you must commit the order around week 3. You firm the suggestion, confirm its receipt lands in or before week 6, and the moment it is committed the projection nets the incoming quantity into the later buckets: week 6 lifts back above 120 and the red clears. You bought while the shelf still read 220, three weeks ahead of the breach, because the projected balance, not the current on-hand, told you when to act.

Keeping the Balance Trustworthy

A purchase decision is only as good as the balance it reads, and the balance is only right if its inputs are. Demand has to be entered, supply has to be firmed and dated inside the horizon, and the planning horizon has to reach far enough to see the breach. A suggestion that never lifts the balance usually means the order is still a proposal, dated outside the horizon, or landing in a later bucket than expected.

The inventory ledger keeps the on-hand starting point honest, receipts and adjustments record the real movements, and the projection nets forward from there. Get those inputs right and the projected balance becomes the single number every purchase reads from. For the wider workflow this sits inside, start from the EDGEBIC planning guide, and to compare the reorder methods a breach can trigger, read min-max vs reorder-point replenishment.