Good plans for cloudy days.

I build tools that make good decisions under uncertainty. Mostly logistics.

A synthetic city, not real data.

Most decisions that matter are made before the facts are in. I build for that moment.

How many loaves to bake before you know the demand.¹ Which order to drive before you know how heavy the day will be.² The usual answer is a forecast and a plan built on it.

I am more interested in a plan that still holds when the forecast is wrong, and in showing honestly how often that happens.

So everything here is built the same way: a real decision you can make yourself, an exact solver that makes it too, and hundreds of sampled days to see who was right.³

Arda HadimiogluMore about me

Fig. 1Under the cloud, most traffic slows. The orange dot takes another street.

Writing

Inventory & replenishment12 min11 Nov 2026

FEFO vs FIFO: the difference, an example and who requires it

FIFO ships the oldest arrival, FEFO the earliest expiry. A dated example where FIFO strands 16 of 48 pallets, who requires which (EU, WHO, US, India) and which racks allow FEFO.

Read the essay

Fig. 2Expected profit by loaves baked. Blue is the forecast, 120 loaves. Orange is the most profitable quantity, 147.

GlossaryWhat is a minimum order quantity (MOQ)?A minimum order quantity (MOQ) is the smallest order a supplier accepts. Below the EOQ it changes nothing; near it, it costs little; at several times the EOQ it costs a lot.
GlossaryWhat is a reorder point?The reorder point is the stock level at which you place the next order: the demand expected during the lead time plus safety stock. 690 + 436 = 1,126 units in the example.
GlossaryWhat is EOQ (economic order quantity)?The EOQ is the order size with the lowest yearly ordering plus holding cost: √(2 × D × S ÷ H). For 12,000 units a year, €60 an order and €2 a unit a year to hold, it is 849.
GlossaryWhat is fill rate in inventory?Fill rate is the share of demand shipped straight from stock. It is not the cycle service level: in the example a buffer for 95% of cycles fills 99.5% of demand.
GlossaryWhat is safety stock?Safety stock is the stock kept on top of expected demand to cover demand above the forecast and late deliveries until the next order arrives. Formula and a worked example: 436 units.
GlossaryWhat size pallet do cold stores use?Cold stores use the standard pallet of their region, the 1200 × 800 mm Euro pallet in Europe or 48 × 40 in in North America. What they limit is height and weight.
GlossaryLot number vs batch numberIn EU food law and in US drug rules a lot and a batch are the same kind of thing, a quantity made under the same conditions; a lot can also be a defined part of a batch. What the number is for.
GlossaryWhat are the standard pallet sizes?ISO 6780 lists six standard pallet sizes, from the 1200 × 800 mm Euro pallet to the 1140 × 1140 mm square. Each in mm and inches, and how many 40 × 30 cm cartons a layer takes.
GlossaryWhat is a Euro pallet?A Euro pallet (EPAL 1, EUR 1) is a 1200 × 800 × 144 mm wooden pallet of about 25 kg with a safe working load of 1,500 kg. What it carries, and what fits on it.
GlossaryWhat is a loading meter (LDM)?One loading meter is one metre of trailer length at the full 2.4 m width, 2.4 m² of floor. A Euro pallet is 0.4 LDM, an industrial pallet 0.5, a 13.6 m trailer 13.6.
GlossaryWhat is a pallet position?A pallet position is one place in a rack or on the floor that holds one pallet. Warehouses fit about 1 to 4 per m² of floor, automated high-bay stores mostly 5 to 8. Why positions are not pallets.
GlossaryWhat is chargeable weight in road freight?Chargeable weight is the higher of a shipment's real weight and a weight the carrier works out from its space, by volume or by loading meters. How road freight does it.
GlossaryWhat is FEFO (first expired, first out)?FEFO ships the stock with the earliest expiry date first, whatever order it arrived in. EU medicines distribution requires it; food warehouses and cold stores use it for dated goods.
GlossaryWhat is FIFO in a warehouse?In a warehouse, FIFO (first in, first out) ships the oldest stock first, by arrival. Not the accounting method. Which pallet racks enforce it, which allow it, and which cannot.
GlossaryWhat is honeycombing in a warehouse?Honeycombing is storage space lost to part-empty lanes or locations that no other product can use. A k-deep lane of one product wastes (k − 1)/2 places on average.
GlossaryWhat is LIFO in a warehouse?In a warehouse, LIFO (last in, first out) means the newest pallet comes out first, as in drive-in and push-back lanes. When that is fine, and when it ages stock.
GlossaryWhat is minimum remaining shelf life?Minimum remaining shelf life is the share or number of days of life a product must still have when it is delivered. Some buyers ask for 75%: a 12-day product must arrive with 9 days left.
GlossaryWhat is pallet overhang?Pallet overhang is cartons sticking out past the pallet's edge. It can add cartons per layer and costs box strength, up to 41% when two adjacent sides overhang.
GlossaryWhat is selective racking?Selective racking is single-deep pallet racking with an aisle beside every row, so every pallet can be reached without moving another. Its selectivity is 100%; its cost is floor space.
GlossaryWhat is TI-HI?TI-HI is the pallet pattern written as two numbers, cartons per layer (TI) and layers (HI). TI × HI is the cartons per pallet. Why TI depends on the layer pattern.
GlossaryWhat is the newsvendor problem?The newsvendor problem picks how much of a perishable product to stock for one period of uncertain demand, when leftovers and missed sales both cost money.
NextMore on routing and fleets is on the way.

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Work

Demos you can play and tools you can use. Each one runs in your browser, nothing is sent anywhere.

Demo
Charge Smart
Drive an electric van's day one block at a time, then see what a weight-aware planner saves. Over 300 sampled days, the median saving is 7.6%.
Play the day
Demo · In the works
Spot or own fleet
Book trucks on the spot market or keep your own. The answer depends on a demand you don’t know yet.
Tool
Trailer fit
Loading meters, pallets per trailer and the weight a carrier will bill, for a mixed consignment, drawn on the trailer floor. Seven published carrier rules and the generic convention, side by side.
Open the tool
Tool
Pallet build
From a packing list of cartons to the pallets it makes: cartons per layer, layers under the height cap, pallets to book, each one drawn with its arithmetic. Hands the pallets to Trailer fit.
Open the tool
Tool
Cold store layout
How many of your pallets a cold room really holds, by rack type: selective, mobile, drive-in, push-back, flow and pallet shuttle, drawn to scale in 3D. A supplier counts places; this counts your stock on an average day.
Open the tool
Tool
Order quantity
The textbook EOQ, then what the supplier allows: minimum order, pack size and price breaks, all-units or incremental. The cheapest order you can actually place, and what each rule costs you a year.
Open the tool
Tool
Safety stock
Safety stock and the reorder point against uneven demand and late deliveries, for a cycle service level or a fill rate, with the difference between the two in units. Paste past demand; it stays in your browser.
Open the tool

Industrial engineering taught me to decide with numbers. Shipping software taught me the numbers have to survive a real Tuesday.

Studied: Industrial Engineering at Boğaziçi Üniversitesi, then Management and Technology at TU München.
Worked: Automation engineer on enterprise systems. Before that, full-stack developer at a Munich product studio.
Made: A data journalism site that reached over 300,000 views, the demos and free tools on this page, and a number of smaller things along the way.

Good plans for cloudy days.

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Writing

FEFO vs FIFO: the difference, an example and who requires it

Work

Charge Smart

Spot or own fleet

Trailer fit

Pallet build

Cold store layout

Order quantity

Safety stock

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