Azithromycin for Injection, 500 mg Vial

Anti-infectivesEssential, 95% service targetPrimary vendor Harborline Pharmaceuticals, lead 1 day, ordered every 3 days63323039810

Stock position

On hand: 229 vial13.8 days of supply
On order: 0 vialnothing open
Forecast rate: 16.6 vial/daynext 30 days
Demand over 4 days: 73 viallead time plus review period
Safety stock: 8 vialempirical 95th percentile of forecast error
Reorder point: 80 vialabove
Stockout: Mon Sep 28
Recommended order: noneby Sun Sep 27
Inventory value: $1,191at $5.20 per vial

How the forecast was made

Exponential smoothing34% weekly error, over-forecast29% worse than naive

A weighted recent average that learns the weekday pattern and any trend. Recent days count more than old ones.

Report card: the model was fit on history up to Tue Jul 21 and scored on the 56 days after. Weekly totals were off by 34% on average (46% day by day), and it over-forecast by 29% overall. A same-weekday-last-week guess would have been off by 26%.

Report card, week by week

Week of	Used	Forecast	Error	Error %
Tue Jul 21	104	141	+37	36%
Tue Jul 28	74	141	+67	91%
Tue Aug 4	109	140	+31	28%
Tue Aug 11	80	140	+60	75%
Tue Aug 18	151	140	-11	7%
Tue Aug 25	105	140	+35	33%
Tue Sep 1	148	140	-8	5%
Tue Sep 8	98	140	+42	43%
All 8 weeks	869	1,123	+254	29%

Weekly totals in vial. Error is forecast minus what was used, so a positive number means the model ran high. This window was hidden from the model when it was fit.

Demand forecast

last 180 days and the next 30

actual forecast, 80% and 95% range what the model said during the report card windowvial/day

The model only knows the usage history. If you know something it does not, a coming surge, a new service line, a product being dropped, adjust the forecast and the stock math follows.

Projected on hand

Projected on hand, vial: today's stock plus open orders on their expected dates, minus the forecast, day by day.

Lots and expiry

Earliest-expiry-first simulation against the forecast. Waste is what remains in a lot on its expiry date.

Lot	Quantity	Expires	Days	Unit cost	Projected waste
L00027	100	Tue Feb 16	155	$5.20	0 vial · $0
L00028	129	Sat May 6	600	$5.20	0 vial · $0

Vendors and prices, last 90 days

Vendor	Part number	Vendor description	Sells by	Paid per vial	Invoices	90-day spend	Pairing
Harborline Pharmaceuticals	63323039810	AZITHROMYCIN MONOHYDRATE 500 MG/5ML VIAL EA	EA of 1	$4.90	31	$5,691	NDC exact
Cobalt Rx Distributors	CRX-56356	AZITHR 500MG/5ML SDV 1CT	EA of 1	$5.10	14	$2,744	reviewed 0.90