Writing a Technical Specification That Gets You the Right Equipment

Tony Miller

Sep 30

6 min read

A specification that names a brand or a bare size, "a trash pump", "a warehouse tent", "chlorine tablets", will get you whatever a bidder chooses to ship. Specify performance, the standard it is tested to, packaging, documentation, warranty and commissioning, then fix your evaluation criteria before you issue the tender.

Why does a vague specification produce the wrong delivery?

Because it leaves every decision that matters to the lowest bidder. "3-inch pump" says nothing about the head it must lift water against or the solids it must pass, so the cheapest 3-inch pump that clears the line item wins, whether or not it can dewater your site. "Warehouse tent, 24x10m" says nothing about the wind load the structure must survive through a season. "Chlorine tablets" says nothing about active ingredient, strength, or the contact time and residual it must deliver, so a compliant-looking bid can still fail at the tapstand.

It is also a quality-control gap, not only a paperwork one: at least 1 in 10 medicines in low- and middle-income countries are substandard or falsified, and a specification that never states an active ingredient, a strength or a testing standard gives a non-compliant product nowhere to be caught before it ships.

How do you specify a pump so you get the right one?

State the duty point, not the pipe size. A duty point is the flow rate against the total head the pump must deliver at that flow, because a pump rated at high flow at zero head will not touch that flow once it is lifting water against real elevation and friction loss. Add the solids size it must pass without clogging, and the suction lift it must self-prime from, since a pump sized for clear water will block on a silted floodwater intake within the hour.

Before: "Trash pump, 3-inch discharge."

After: "Diesel-driven self-priming trash pump. Duty point: minimum flow of 800 L/min at 15 m total dynamic head. Solids handling: minimum 25 mm. Suction lift: self-primes to at least 6 m. Bidder to submit the manufacturer's published performance curve confirming the stated duty point." A pump such as the Multiquip QP3TH, rated up to 1,500 L/min, solids to 37 mm, maximum head 95 ft (29 m) and suction lift to 7.6 m, is the kind of published datasheet a bidder should be made to produce against your stated duty point, not a brand name taken on trust. Our own pump equipment range is specified this way against duty point, not discharge size alone.

How do you specify a warehouse tent so span and load are not left to the bidder?

State the clear span, the eave height and the load rating the structure must be certified against, not the footprint alone. Footprint tells a bidder how much ground you want covered; it says nothing about whether the frame will still be standing after the first storm of the season, and a specification that omits the load rating lets a lightweight frame compete against an engineered one on the same line item.

Before: "Warehouse tent, 24x10m."

After: "Modular storage structure. Clear span: minimum 10 m, no internal support columns. Eave height: minimum 3 m for stacked pallet storage. Wind and snow load rating: bidder to state the design load in km/h (or kN/m²) and the structural standard the frame is certified against, with the manufacturer's engineering certificate attached. Cladding: rated for the local wet season, with a minimum design life stated in years." Ask for the certificate, not the adjective; a bidder who cannot produce one has not had the frame engineered for your site, whatever the brochure claims about wind resistance. Our own modular warehouse structures are specified against exactly this kind of stated load and span, not a footprint alone.

How do you specify water treatment product so it actually disinfects?

State the active ingredient, the tablet strength, the litres it treats per tablet, and the residual it must hold, not just "chlorine tablets" or a brand name. Two products with the same brand family can carry different strengths, and a specification that does not fix the strength cannot catch a substitution.

Before: "Water purification tablets."

After: "Water purification tablets, active ingredient sodium dichloroisocyanurate (NaDCC), tablet strength 67 mg. Each tablet to treat 8 to 10 litres of clear water at a 30-minute contact time. Delivered water to achieve free residual chlorine of at least 0.2 mg/L at point of delivery, per the Sphere/IFRC WASH standard. Bidder to confirm authorised-distributor status for the named manufacturer." NaDCC is Medentech's own stated active ingredient for its Aquatabs range, and the 8 to 10 litres per tablet at 30 minutes' contact is the manufacturer's own dosing instruction, not a house rule of thumb, per the CDC-published Aquatabs instruction sheet. Stating strength and standard, not just "tablets", is what lets you reject a substitution at goods-inward rather than discover it mid-outbreak. See our water treatment product range for how these lines are held in Juba stock.

What else belongs in the specification besides the performance line?

Six items that buyers routinely leave to the bidder's discretion, and should not:

Packaging. Export packaging suited to a road corridor, not a European warehouse floor; state the packing unit and whether it must survive stacking and rough handling.
Marking. Batch numbers, expiry dates where applicable, and language of labelling, so goods can be tracked and rejected line by line at inspection.
Documentation. Certificate of conformity, manufacturer's test certificate, and, where relevant, the authorised-distributor letter confirming the bidder is entitled to sell the named product.
Warranty. State the warranty period and what it covers, spare parts, labour, or replacement, and who bears the freight cost of a warranty claim from your site.
Spares. Require a first-line spares list with the bid, not a promise to supply spares later once a fault has already taken equipment out of service.
Commissioning. State whether installation, yield-testing or handover training is included, or priced separately, so it cannot be assumed away after award.

A specification silent on any of these six pushes the decision to the supplier who benefits most from ambiguity, and that is rarely the supplier best placed to support you after delivery.

How do you set evaluation criteria before you issue the tender?

Fix the pass/fail line and the scoring weights before the tender goes out, not after bids arrive. Decide which items are pass/fail, a pump that cannot meet the stated duty point does not get scored, it is disqualified, and which are weighted, delivery lead time or warranty terms, for example, carrying a stated percentage rather than a binary cut. Publish the weighting in the tender document. A committee that only sets its criteria after seeing the bids ends up favouring whichever bidder looks best on the day, the same failure as a vague specification, arrived at from the other direction.

Frequently asked questions

What is the difference between specifying a brand and specifying a performance standard?

A brand name tells a bidder what to write on the quote, not what the equipment must do. A performance standard, a pump's duty point, a tent's load rating, a tablet's strength and residual, states the outcome the equipment must achieve, so any compliant bidder, authorised or not, has to meet the same bar. Naming a standard also gives you grounds to reject a bid that cannot meet it, which a brand name alone does not.

Why does specifying only a pipe size, like "3-inch pump", cause the wrong pump to be delivered?

Because pipe size says nothing about the flow the pump must deliver at the head it will actually work against. A Multiquip QP3TH and a cheaper 3-inch pump can share a discharge size while differing sharply in rated flow, maximum head and solids handling, and only a stated duty point catches that difference before the pump arrives on site.

Does a warehouse tent specification need to state a load rating even for a short-term deployment?

Yes. A structure without a stated wind and snow load rating and a supporting engineering certificate can be quoted as a lightweight frame at the same line item as an engineered one, and the difference will only show up in the first bad storm. State the clear span, eave height and load rating, and require the manufacturer's certificate with the bid.

Why does a water treatment specification need to state active ingredient and tablet strength, not just "chlorine tablets"?

Because strength determines both the litres a tablet treats and the contact time needed to reach a safe residual. Medentech's own dosing instruction for its 67 mg Aquatabs states 8 to 10 litres per tablet at a 30-minute contact time, per the CDC-published instruction sheet, and the delivered water must still reach the Sphere/IFRC free residual chlorine standard. A specification silent on strength cannot catch a weaker substitute before it reaches an outbreak response.