Ask how many smart safety harnesses a project needs and the honest answer is that the harness count and the monitor count are decided by three different questions: how many people are aloft at once, how the crews rotate, and what the inspection cycle takes out of service at any time.
One harness, one worker
A harness is body-worn PPE. Sizing, belt position and adjustment differ from person to person, and a shared harness is neither comfortable nor hygienic. Smart harnesses add a data reason on top of the human one: usage records and violation records only mean something when they attach to a named individual — who was aloft, and whether the harness was worn and anchored correctly.
That makes one harness per assigned worker the basic unit of configuration. It is also the unit the monitor assumes: the SBM2000-series harness monitor is paired with a harness and its wearer, so the record trail runs person by person.
Size to simultaneous headcount, then add spares
Start from the largest number of people at height at the same time — that is the base quantity. Crews working two shifts can size to simultaneous headcount rather than total roster, which is where most over-buying happens in the other direction. Then add one or two spare sets per crew for the sets that are out of service: sent for inspection, in repair, or on charge.
Where several crews share one pool of equipment, the arrangement needs administration rather than more units: stagger work times, and log where each set is. The failure mode is not running out of harnesses; it is a crew on the workfront unable to find one usable, accounted-for set.
Monitors are issued per person; the platform is opened once
The harness monitor is issued together with the harness, per person — it watches anchorage state, wear state and the wearer's activity, alarms on the violation and uploads the record. The monitoring platform does not scale with headcount: one deployment per project or per company, and supervisors see the whole picture on phone and desktop. Budget the two separately, or the platform line item gets squeezed by the harness count and the data side arrives late.
Four checks before ordering
First, the harness itself: conformity with GB 6095-2021 and third-party test reports for the model you are buying, not the product family. Second, alarm accuracy against your real work conditions — a trial on the actual workfront is worth more than a specification sheet. Third, battery life and charging routine, checked against the crew's shift pattern rather than the laboratory cycle. Fourth, whether the data reaches the safety management platform you already run; equipment that produces records nobody can open becomes another data island.
Two questions that come up on every project
Does the attendant need a smart harness? Attendants work at ground level and are normally not issued height-work equipment. If the attendant enters an elevated work area with the crew, issue to the same standard as the workers.
Can we retrofit a smart module to harnesses we already own? We advise against it. The module and the harness body are designed and type-tested as one assembly; a field retrofit has no test basis behind it, and after an incident nobody can say what the arrangement was actually rated for.
The count is arithmetic; the utilisation is management. One set per assigned worker, sized to simultaneous headcount for shift crews, plus spares for the inspection cycle — and a log that says where every set is. Get the last part wrong and no quantity will be enough.