How to size Min & Order Quantities for Arda Cards

What you’ll set

• Min Qty: the on-hand stock level that triggers a scan.
• Order Qty: how much you add to the cart when you scan.

• Use Weekly as your default sizing period. It’s fine to change the period if it makes the math simpler.
• • Avoid Daily unless use is >1 per day and level across the week.
  • Avoid Monthly unless weekly use is <0.5 or demand is very choppy.
• Lead time = trigger to shelf: from the card being dropped to stock back on the shelf.
• Include time in the drop bin, time to scan and place the order, supplier ship time, receiving, and restocking.
• • If you don’t know: assume 1 week for reliable vendors, 2 weeks for average vendors, 3 weeks for unreliable vendors or items that you may sit on to accumulate items before ordering.
  • Make a gut call and refine after a few orders. Use Receiving in Arda so you can measure real lead times.

Step 1 — Estimate “Likely Max” weekly use

• If you have a little data
• LikelyMaxWeeklyUse = max( Avg(last 4 weeks) × 1.25 , Highest single week in last 8 )
• If you have no data
• Assume a reasonable amount (see Step 2 examples), then tune after a few orders.

Step 2 — Set Min and Order Qty (the easy button)

• If sold in packs/cases, start with 1 pack.
• If sold as each, pick a tidy lot (3, 5, 10) that matches the job.
• If one pack is smaller than a few weeks of Likely Max, buy the smallest whole-pack multiple that covers a few weeks.

• 1 pack of 20 pens
• 1 pack of paper towels (6 or 12 rolls)
• 3 heavy-duty box cutters
• 2 packs of 2 #2 Phillips head bits (4 total)
• 2 reams of printer paper
• 1 set of printer ink (CMYK or model set)
• 1 box of M8 bolts (≈50)
• 1 case of nitrile gloves (10 boxes × 100)
• 1 bag of zip ties (≈100)
• 1 six-roll pack of packing tape

Step 3 — Set Min and Order Quantity Based on Usage

• BaseMin = LikelyMaxWeeklyUse × (LeadTimeWeeks + 1)
• ConservativeMin = 1.33 × BaseMin  (+33% buffer)
• Round up to whole packs or MOQ.

Tip: If the arithmetic is easier in a different period (daily for fast movers, monthly for very slow movers), do the math in that period, apply the same 33% buffer, then round to pack/MOQ.

Step 4 — Check shelf space

• MaxOnShelf (units) ≈ Min + OrderQty
• MaxOnShelf (packs) ≈ ceil( (Min + OrderQty) ÷ PackSize )

Step 5 — Enter values in Arda and print cards

• Add Min and Order Qty on the item page.
• Place the printed card in front of the Min quantity so you can’t access Min without moving the card.
• Trigger an order if you are below Min.

Step 6 — Review and tune

• After 2 scans:
• • If you stock out, raise Min (or fix lead time) and keep Order Qty steady.
  • If you overflow, lower Min or reduce Order Qty (you can break the “Order Qty = Min” default).
• After 30–60 days: confirm period, lead time, and Likely Max.
• If stable, reduce the buffer from +33% → +20%:
• StableMin = 1.20 × BaseMin (then round to pack/MOQ).

Cost trap: “bulk discounts” that cost more

1. Storage space cost rises (bins, shelves, floor space).
2. Obsolescence risk increases (design changes, supplier supersedes parts).
3. Carrying cost of capital goes up (cash tied on the shelf).
4. Damage, shrink, or expiry risk grows with time-on-shelf.
5. Handling and counting labor increases (more put-away, more cycle counts).
6. Overflow and mispicks happen when bins don’t fit larger lots.
7. Cash-flow impact and approval friction increase with bigger buys.
8. Slower learning—big lots delay feedback, so tuning takes longer.

Worked examples (with Order Qty = Min by default)

• LikelyMaxWeeklyUse = 15; LeadTimeWeeks = 1
• BaseMin = 15 × (1+1) = 30
• ConservativeMin = 1.33 × 30 = 39.9 → Min = 40 (2 packs)
• Order Qty = Min = 40 (2 packs)
• Shelf check: 40 + 40 = 80 pens = 4 packs

• BaseMin = 12; ConservativeMin = 15.96 → Min = 24 (2 packs)
• Order Qty = 24 (2 packs)
• Shelf check: 24 + 24 = 48 rolls = 4 packs

• LikelyMaxWeeklyUse = 2; LeadTimeWeeks = 2
• BaseMin = 6; ConservativeMin = 7.98 → Min = 8
• Order Qty = 8
• Shelf check: 16 each

• LikelyMaxWeeklyUse = 3; LeadTimeWeeks = 1
• BaseMin = 6; ConservativeMin = 7.98 → Min = 8 bits (4 packs)
• Order Qty = 8 bits (4 packs)
• Shelf check: 16 bits = 8 packs

• LikelyMaxWeeklyUse = 750; LeadTimeWeeks = 1
• BaseMin = 1,500; ConservativeMin = 1,995 → Min = 2,000 (4 reams)
• Order Qty = 2,000 (4 reams)
• Shelf check: 4,000 sheets = 8 reams

• LikelyMaxWeeklyUse = 0.25; LeadTimeWeeks = 1
• BaseMin = 0.5; ConservativeMin = 0.665 → Min = 1 set
• Order Qty = 1 set
• Shelf check: 2 sets

• LikelyMaxWeeklyUse = 80; LeadTimeWeeks = 2
• BaseMin = 240; ConservativeMin = 319.2 → Min = 350 (7 boxes)
• Order Qty = 350 (7 boxes)
• Shelf check: 700 bolts = 14 boxes

• LikelyMaxWeeklyUse = 1,200; LeadTimeWeeks = 1
• BaseMin = 2,400; ConservativeMin = 3,192 → Min = 4,000 (4 cases)
• Order Qty = 4,000 (4 cases)
• Shelf check: 8,000 gloves = 8 cases

• LikelyMaxWeeklyUse = 90; LeadTimeWeeks = 1
• BaseMin = 180; ConservativeMin = 239.4 → Min = 300 (3 bags)
• Order Qty = 300 (3 bags)
• Shelf check: 600 ties = 6 bags

• LikelyMaxWeeklyUse = 8; LeadTimeWeeks = 1
• BaseMin = 16; ConservativeMin = 21.28 → Min = 24 (4 packs)
• Order Qty = 24 (4 packs)
• Shelf check: 48 rolls = 8 packs

If the shelf-space check fails or capital is too tight, break the “Order Qty = Min” default and use a smaller Order Qty, dedicate more shelf space, or adjust your period or Likely Max.