90 x 90 mm Aluminium Profile Supply: Stock Planning and Lead Time

01Where should the stock actually sit?

One place, in almost every case. The instinct is to hold a little stock at each site so that nobody waits, and the arithmetic usually says the opposite: three small stocks carry more total capital than one larger one, because each has to cover its own variability, and none of them can help the others.

The exception is when the sites are far enough apart that a transfer costs more than the extra stock. Pune to Nagpur is about 700 km, which is a day and a half by road and a real cost per tonne. Beyond roughly 500 km, a second stocking point starts to make sense for fast-moving sections, and for a slow-moving section like 90 x 90 it usually still does not.

• Central stock at one site, with a defined transfer time to the others. That time becomes part of the lead time, not a surprise.
• Keep a small buffer at the second site only for the sections that are used weekly, not for the ones used quarterly.
• For a section at 7.60 kg/m, a 6 m length is 46 kg: handling needs two people or a trolley, which affects how much stock a small site can physically hold.
• Do not stock the same section at three sites in three anodising lots. That is the colour problem waiting to happen, described below.

02How much safety stock does the distance actually require?

The standard model is safety stock equals Z times the standard deviation of demand times the square root of the lead time, with demand and lead time in the same unit. The square root is the part people skip, and it is the part that makes distance less frightening than it feels.

A worked example. Suppose the demand for this section is 120 m a day with a standard deviation of 40 m, and the replenishment lead time is 12 days for a domestic transfer. At a 95 percent service level, Z is 1.65. Safety stock is 1.65 times 40 times the square root of 12, which is about 228 m. If the lead time doubles to 48 days for an import, safety stock becomes 1.65 times 40 times the square root of 48, about 456 m. Doubling the lead time increases the buffer by a factor of two, not four.

03What does the lead time map look like?

Four destinations matter for most Maharashtra buyers, and the difference between them is inland transit rather than ocean. The ocean leg is common to all of them.

Add the production lead time to these figures, not to the sailing alone. For a 90 x 90 with an existing die and mill finish, production is 12 to 20 days, so a Nagpur delivery is realistically 32 to 50 days from order. That number, not the sailing, is what the safety stock has to cover.

04What does a monsoon do to stored anodised stock?

It pits it, in the slots, where water sits. An anodic film is corrosion resistant because it is a barrier, and a barrier works while it is intact and while the environment is not permanently wet. Water standing in an open slot for weeks is the one condition the film handles worst, and the pits that form are inside the slot where nobody sees them until assembly.

The practical controls are cheap: store under cover, store at an angle so water runs off rather than sitting, keep the bundles off a damp floor on timber, and do not remove the interleaving until the material is issued. For long storage, a strippable tape on the open slots costs very little.

05How do you keep one batch traceable across three cities?

By treating the batch as a unit and splitting it deliberately, rather than by ordering three times and hoping. The mechanism is simple: one extrusion lot, one anodising rack load, one heat number, split into bundles that are labelled with the same reference before they leave.

The failure mode is subtle. Two anodising lots of the same section look identical in isolation and different side by side, because film thickness varies with position on the rack and a thicker film reads darker. If the two lots go to two cities, nobody notices until a project spans both sites.

The cost of the single lot is that the total quantity has to be committed at once, which is working capital. The cost of three lots is a colour mismatch across sites, which is usually more expensive and much harder to fix after the frames are built.

06What five numbers should be on the enquiry?

A multi-site enquiry needs the split and the schedule, not just the total.

Total quantity and split

metres per site, because the bundle allocation follows the split

Delivery dates per site

staggered deliveries change the production planning

Finish and colour

one rack load per colour, stated so the lots are not split

Length and cut

6 m stock or cut to list, per site

Storage at destination

covered or open, because it changes the packing advice

Section

90 x 90 mm eight slot at 7.60 kg/m, or the heavy wall at 9.00 kg/m

Related sections and categories

The 90 x 90 is listed under 45 Series Aluminium Profiles, with the heavy wall version at 9.00 kg/m. For lighter frame work the 45 x 90 mm six slot section at 4.10 kg/m halves the freight per metre.