“Safe by Design” Is Not Enough — You Need “Safe by System”

When a robot manufacturer says “safe”, they mean the machine itself: its housing, its sensors and the way it stops. That, however, is only half of the equation, because a safe system of work with robots is created not in the design of the device but in the space you build around it. In this article we show the difference between the “safe by design” and “safe by system” approaches and explain why even the best-designed robot still needs a well-organised facility to be truly safe.

“Safe by design” — what the robot manufacturer takes on

The market for mobile and humanoid robots is moving ever more clearly towards safety built into the machine itself. A good example is Amazon’s acquisition of the Fauna Robotics team, which was developing the Sprout robot with a safety-first logic. As The Robot Report describes, the designers opted for a lightweight construction, a soft housing material and the minimisation of so-called pinch points, i.e. places where crushing or trapping can occur.

This is exactly what “safe by design” is: safety that the engineer builds into the product. It includes limits on weight and speed, obstacle detection systems, a controlled emergency stop, rounded edges and guards on moving parts. All of this genuinely reduces risk and is essential. But it has one fundamental limit: it ends at the outline of the machine. A manufacturer can design a robot so that it will not injure a person of its own accord. What it cannot do is design, on your behalf, the facility in which that robot will move.

Why a safe machine does not yet make a safe system of work with robots

Imagine the ideal robot: soft, slow, stopping instantly. Now let it into an area where an unmarked transport route crosses a pedestrian walkway, rack corners protrude into the travel path and operators do not know where the machine will go in ten seconds’ time. The robot is still “safe” in the design sense, but the situation around it no longer is. The risk has not disappeared — it has moved from the machine into the space.

That is the difference between “safe by design” and “safe by system”. The first says: the machine will not cause harm of its own accord. The second asks: is the environment in which the machine works alongside people and trucks predictable, legible and physically organised? A safe system of work with robots is only the sum of both layers. The manufacturer is responsible for the first. You are responsible for the second — and it is this second layer that is most often underinvested in.

The more “intelligence” goes into the robots themselves, the easier it is to fall into the illusion that the facility no longer needs attention. The opposite is true. An autonomous machine works well only in an environment that people and systems understand as unambiguously as it does.

Four places where risk arises outside the robot

If the manufacturer takes on the safety of the machine, where does the rest of the risk lie? Almost always in the same four places — and each of them lies outside the robot, in the organisation of the space.

• Pinch points in the surroundings. The manufacturer minimises crushing points on the machine itself, but racks, structural columns, doors and narrow passages still create points where a person can be trapped between the robot and a fixed element of the facility. This is an environmental risk, not a design one.
• Mixed zones. The most difficult are the places where robot traffic, operators and manual transport intersect. There it is not enough for the robot to “see” the person — the person must also know in advance where their space ends and the machine’s path begins.
• Route legibility. How people react depends on whether they understand where the robot is going. If the route is not visible from a few metres away, the operator only finds out about it when the machine is already close. That is too late for a calm decision.
• Location identification. Drop-off points, pick-up points and buffer zones must be unambiguous. “Put it wherever there is space” does not scale with autonomy — an ambiguous location means ambiguous behaviour in an area where a machine is moving.

None of these four problems will go away if you swap the robot for a better model. They are not defects of the machine — they are gaps in the system of work around it.

“Safe by system” — four pillars of a safe space

“Safe by design” should therefore have a second pillar. “Safe by system” means deliberately designing the space so that it limits risk regardless of how good the machine is. It consists of four elements that correspond exactly to the four risk points from the previous section.

Clear zone boundaries

Physically separating robot traffic from people and manual transport is the foundation. Permanent boundaries are built with barriers — where a collision is a real possibility, Raysan flexible barriers do the job well, absorbing the impact energy and protecting both the machine and the infrastructure. For zones that change seasonally or during maintenance work, it is worth having relocatable solutions, for example ZonePro mobile barriers.

Protecting collision points

Pinch points in the surroundings are neutralised one by one: rack corner guards, protection for columns and doors, and fencing wherever a pedestrian walkway comes close to a transport route. This is the cheapest layer of the system, yet it prevents the most serious incidents. A dedicated category, Pedestrian Barriers, is devoted to organising walkways for people.

Unambiguous location identification

Drop-off points, buffer zones and pick-up points are marked so that they are the same for people and for the system. A repeatable “always the same way” standard turns guesswork into a rule and shortens the reaction time when something deviates from the norm.

Visual traffic guidance

Routes, intersections and decision points must be legible from a distance and in poorer lighting. The aim is for the operator to “read” the traffic rules in a few seconds, without training and without having to think. The predictability of the environment is just as important as the predictability of the machine.

How to build “safe by system” in your facility

The transition from a safe machine to a safe system of work with robots starts with a map, not with a purchase. Before you assess the robot, assess the space around the future route.

1. Mark the collision points on the layout: rack corners, columns, doors, narrow passages and places where a pedestrian walkway meets a transport route.
2. For each point, decide whether you need a permanent barrier, a corner guard, fencing or a mobile solution.
3. Check whether the robot’s route is visible from a few metres away and whether an untrained operator understands where they can move.
4. Standardise drop-off points and buffer zones — one marking standard for the whole facility.
5. Verify consistency between shifts: boundaries and rules must look the same in the morning and on the night shift.

These “boring” elements decide whether the robot will be a support or a source of friction. A machine designed to be safe gives you the first pillar for free. You have to put up the second one yourself — and that is what distinguishes a facility that has merely bought a robot from one that genuinely works with it.

Summary — what to pay attention to

• “Safe by design” is safety built into the machine: weight, speed, sensors, a soft housing, fewer pinch points. The manufacturer takes it on.
• “Safe by system” is safety built into the space: zone boundaries, collision protection, location identification, traffic guidance. You take it on.
• The risk that the manufacturer cannot remove arises outside the robot — in the surroundings, mixed zones, route legibility and drop-off points.
• A better robot will not fix a disorganised facility; start with a risk map, not a machine catalogue.
• A safe system of work with robots is the sum of both pillars — one without the other leaves a gap.

What is the difference between “safe by design” and “safe by system”?

“Safe by design” is safety built into the machine itself by its manufacturer — its construction, sensors and the way it stops. “Safe by system” is safety organised in the space around the machine: zone boundaries, markings, protection of collision points and legible routes. Only both pillars together create a safe system of work with robots.

Isn’t a well-designed robot enough on its own?

No. Even a lightweight, slow robot well equipped with sensors operates in surroundings that the manufacturer does not control. Racks, columns, doors and traffic intersections still generate risk, and how people react depends on whether they understand the machine’s route. Design safety is necessary, but not sufficient without an organised space.

Where should you start building “safe by system”?

With a map of the collision points on the facility layout. Mark the corners, columns, doors and places where people meet a transport route, then match a barrier, guard or fencing to each of them. The next step is to standardise the markings of routes and drop-off points so that they are unambiguous for both people and the system.

Sources

• The Robot Report, “Amazon acquires humanoid developer Fauna Robotics” — https://www.therobotreport.com/amazon-acquires-humanoid-developer-fauna-robotics/