In industry publications on security, we read that “physical security systems form a tangible layer of protection in urban spaces, complementing electronic solutions.” The word “complementing” shows how far we have strayed from the fundamentals of security design. Today, doors, grilles, shutters, locks and fences are treated as an “unwanted addition” to electronics. In reality, the opposite is true — from the standpoint of protection effectiveness, the physical barrier takes priority.
Every effective protection system rests on three pillars: physical resistance, detection and intervention.
Every effective protection system rests on three elements — the so-called iron triad of security, arranged in a specific order:
- Physical resistance (O) — doors, locks, glass, grilles, shutters, fences. They buy time.
- Detection and alarming (A) — sensors, intrusion and hold-up alarm systems. They inform about an attack.
- Intervention (I) — neutralising the threat through the arrival of a patrol, police or internal security. The real response to an event.
The golden rule is: the resistance time of the barrier must exceed the sum of the time from the start of the attack to detection and alarming, plus the time from receiving the alarm to launching an intervention. If this inequality is not satisfied, the monitoring system serves only to review the theft in high definition.
Case study 1: Optical salon in Poznan
A break-in at an optical salon — branded eyeglass frames worth nearly PLN 500,000 were stolen.
Timeline of the event:
- forcing the door: 67 seconds,
- stealing the goods: approximately 2.5 minutes,
- total duration: just under 4 minutes.
The patrol arrived 5 minutes after receiving the alarm signal. If the alarm was triggered while the door was being attacked, perhaps only a minute was missing. However, the burglars likely received an additional “bonus” in the form of an entry delay in the alarm system from the moment the door was opened — a standard installation practice.
The PLN 20,000 reward for help in apprehending the perpetrators would have been enough to fund solutions that would have raised the risk on the burglars’ side. The key question is: with a longer door resistance time — assuming a working alarm and rising noise — would the burglars have continued their attempt?
Case study 2: Currency exchange attack in Szczecin
Attackers armed with heavy hammers struck the glass more than 50 times. The glass cracked but did not give way — it withstood the kinetic force. Staff triggered the hold-up alarm, and the attackers — aware that time was running out — gave up and fled before the police arrived.
The physical barrier discouraged the attackers, making the assault unviable in terms of time. The surveillance system recorded evidential material for the police, and the property was saved by mechanics, not pixels.
Back to basics in the age of AI
AI in surveillance is the future of threat identification, yet there is no digital cure for all ills. At conferences, salespeople sell a “sense of security” based on gadgets — megapixels, analytics, integrations. Meanwhile, those responsible for protecting assets must take a holistic view.
Each parameter of the triad (O, A, I) must be:
- realistically measured,
- consciously selected,
- consistent with the character of the facility and the risk assessment.
Without a sufficiently strong physical barrier, even the best electronic system is merely a source of evidence after the fact.
Security is a game of time
Rather than first asking about camera resolution and AI features, it is worth asking: how long will my doors, glass, grilles or fences hold before it is possible to respond to the alarm? How fast will the response be?
If the answer is “less than the time it takes to arrive and intervene” — the protection system is illusory, regardless of the number of megapixels. Security is a game of time. And time is bought by physical resistance — not an algorithm.