The whole category in one page.
DATA NOBODY ACTS ON PRODUCES NOTHING
Establish what decision changes before deploying anything, and measure whether the system changes outcomes rather than whether it collects readings.
THE ONGOING COST USUALLY EXCEEDS THE HARDWARE
Connectivity, platform, batteries, maintenance and support, multiplied by fleet and years. Model full scale from pilot figures, not estimates.
IF A SITE VISIT COSTS MORE THAN THE DEVICE, THE DEVICE MUST NEVER NEED ONE
Which drives everything: long battery life, remote update, self-diagnosis, and design for swap rather than repair.
TRANSMISSION DOMINATES POWER, SO SEND LESS
Report by exception, aggregate into fewer messages, and always send a heartbeat — otherwise a dead device looks identical to a stable one.
DISCONNECTION IS NORMAL, NOT EXCEPTIONAL
Buffer locally, timestamp at the reading rather than the transmission, and randomise reconnection so the fleet does not flood the platform at once.
UNIQUE CREDENTIALS PER DEVICE, AND VERIFIED UPDATES, ARE NOT OPTIONAL
A shared secret compromises the fleet, and an unpatchable device stays exploitable permanently. Your devices are a risk to others, not only to you.
A WRONG ACTION CAUSES PHYSICAL CONSEQUENCE
Enforce limits on the device, define the safe state, and never put a network connection in a safety path.
