Buttons, zips and labels: counting small trims quickly and accurately

Eight thousand buttons in a box, 500 zips in a bag, thousands of labels on a reel: counting trims one by one is slow and confusing for the person counting. A button or zip is worth little, yet a model can sit waiting on the production line for missing trims. With the right method a trims count is quick and accurate enough. Here are three methods and when to use each.

Method 1: counting by standard pack

Sealed packs from the supplier carry the quantity: a bag of 1,000 buttons, a bundle of 100 zips. Sealed packs are counted as pieces, and opened packs go on a separate line. To trust the sealed packs, run a small check: one pack in ten is opened at random and counted. If it agrees, the other packs are accepted by their labels. If it does not, all packs from that supplier become suspect and more packs are opened; it is also a finding to feed back to the supplier at goods receipt. Tape the opened pack shut and stick on a label saying "checked, date, signature", so you do not have to open the same pack a second time.

Method 2: counting by weight

For loose buttons, rivets and snaps in an open box, counting by weight is used. The steps are:

1. Separate parts of the same size and colour without mixing them.
2. Tare the empty container.
3. Count out a sample of 500 and weigh it; unit weight = weight ÷ pieces.
4. Weigh the net contents of the container.
5. Pieces = net weight ÷ unit weight.

An illustrative case: 100 buttons weigh 85 g, so the unit weight is 0.85 g. If the container's net weight is 12,750 g, then 12,750 ÷ 0.85 = 15,000 buttons. But if the scale reads in 1 g steps, 85 g may really be between 84.5 and 85.5 g; the unit weight lies between 0.845 and 0.855 g and the result swings between about 14,912 and 15,088, roughly ±90 pieces (0.6 per cent). Use a sample of 500 buttons (425 g) and the uncertainty falls to 0.5 ÷ 425 = 0.12 per cent, one fifth of that. A heavier sample shrinks the scale error. Do not mix up the weighing container and the sample container, and check the scale's zero before every measurement; with materials that absorb moisture, such as wooden buttons, the weight can change with the air.

Method 3: length-based and reel items

For tape, elastic and zip chain that arrive by length or on reels, what is counted is the reel. The metres or pieces on the label are read and multiplied by the number of reels, while opened reels are actually measured. If a reel label says 500 pieces and the count finds 12 reels, the record should show 12 × 500 = 6,000 pieces; for an opened reel the remaining quantity is measured. Zips differ by length and colour, so they are separate items: 18 cm and 20 cm zips are not added on one line.

Mixed boxes

The item that wastes the most time in a count is the mixed box. Different sizes or colours in a box are separated before the count and each type is written on its own line. In a box of 1,000 with three sizes mixed, taking a separate sample from each size and weighing each is far safer than getting a wrong total from a single sample. The cost of sorting is paid once, because if boxes are then stored in the new order the mix-up does not return at the next count.

Record unit and weighing unit are not the same

On the item card the main unit is usually the piece. The scale is only a means of finding the number of pieces; the count result is written in the unit on the item card (pieces). If an item is held in kg, the weighing result is already the main unit and no conversion is needed. Where there are two units, the conversion must be written on the card.

In short

Using the pack, the scale and the sample check together, instead of counting trims one by one, shortens the time and makes the error measurable. In factory warehouse counts StockSystem counts fabric rolls by metres and lot and trims and packaging by piece, and every line is written in the unit on the item card.