Forecasting hair-treatment stock from booked courses

A dermal filler order is a forecast. You are buying against demand that has not walked through the door, and if it does not arrive you are holding stock. Hair treatments work differently. Because they are usually delivered as a course across multiple appointments rather than in a single visit, a patient who has paid and had a first session represents product you are obliged to have on the shelf later. Six patients starting a course is not six units of demand. It is a schedule.

Committed demand is not last month's sales

A sales report tells you what left the shelf. For this category it does not tell you what you owe. Courses that started late in a quarter carry most of their consumption into the next one, so the period you have just closed can look quiet while the obligation sitting in the diary is heavy. The reverse happens too: a strong month of completions leaves a book with nothing committed in it, and reordering to match that month buys stock nobody has asked for.

So the forecast has two inputs, and only one of them is a guess. Committed demand is arithmetic — patients mid-course, sessions remaining, units per session, taken from the protocol your practitioners actually run. New starts are the estimate. Keeping the two apart is the discipline. Blended into a single line on a purchase order, you lose the ability to see which half of the number you can rely on, and it is always the committed half that must not be short.

Build the forecast from the diary

This is a half-hour job at the start of a quarter if the information is written down as courses are sold, and an afternoon of reconstruction if it is not.

• Every patient currently mid-course: which product they are on, and how many sessions remain.
• The units each remaining session draws, taken from your clinic's protocol and cross-checked against the manufacturer's IFU rather than from memory.
• Courses sold but not yet started — committed in the same way, just not visible in usage yet.
• Expected new starts, given as a range rather than a single figure, and tied to something real: a campaign already booked, a referral pattern you have seen before, a practitioner joining or leaving.
• How each product is packed, since a course drawn from a multi-unit pack counts differently from one supplied per treatment.
• The expiry window on stock you already hold, checked against the date of the last session you are committing to.
• Any protocol or product change a practitioner is planning before the quarter ends.

What breaks mid-course

This is the part that makes hair stock different from filler stock. Running out of a filler costs you a booking. Running out of a product a patient is several sessions into costs you a clinical decision — whether to continue with something else, pause, or start again — and that decision belongs to the treating practitioner. It should not be discovered on the morning of the appointment, which is what happens when nobody has checked the shelf against the diary.

Supply breaks mid-course in more ways than simply running out:

• the manufacturer changes the presentation, pack size or pack contents
• a batch is delayed in transit or held at import
• a product is reformulated, renamed or withdrawn from a market
• the only stock available is short-dated relative to the course still to run

None of these is unusual and none of them shows up in a usage report until it is too late to plan around. Four habits absorb most of the damage. Ring-fence stock allocated to committed courses so routine ordering cannot quietly consume it. Record the lot number against the patient at every session, so that if anything changes you know precisely who is affected rather than guessing. Ask your supplier about continuity when you place the order, not when you reorder. And size whatever buffer you keep against committed courses specifically, not against total category volume — the buffer exists to protect promises, not throughput.

Questions to put to the supplier first

• Is this product's presentation or pack size changing in the next few months, and would it stay under the same name if it did?
• What expiry dating will arrive on the batch you would ship me now — and does it cover a course that starts at the end of the quarter?
• If it goes out of stock mid-quarter, what is the realistic lead time, and will you tell me before I notice?
• Can a quarter's stock be staged across the quarter rather than shipped at once, if storage or dating makes that better?
• What documentation comes with each batch, and is it batch-specific?
• How do the bulk tiers apply — per order, or across a period — and does a staged shipment still qualify?

Buying to a tier, not to a write-off

Bulk tiers reward buyers who commit, and committed course demand is the safest volume there is to commit against, because it is already sold. The constraint is not the tier, it is the dating. Work out the last date the last session of your longest booked course will draw on that stock, and do not buy past it to reach a discount. Past that date, the tier is buying stock you will throw away. The second constraint is physical: a quarter of stock has to be storable under whatever conditions the IFU specifies, and a full fridge is a reason to stage deliveries rather than a reason to under-order.

Pack size and pack contents are listed against each product under /store/hair-treatments; bulk tiers appear once your trade account is approved, and the dating on the batch that would actually ship is worth confirming with us before you commit a quarter to it. The course arithmetic is the part only your diary can supply.

A system is more than this needs. One row per patient mid-course, updated the day a course is sold rather than the day the shelf looks empty, does most of the work. What matters is only that the quantity on the purchase order traces back to appointments you have already promised to keep, and that when a specific figure decides something, it comes off the box rather than out of anyone's head.