There are 36 types of accidents that can be distinguished, combined in 7 categories.

The categories are:

The most important causes and effects of 36 types of accidents are combined in so-called Facts and Figures. They describe for every type of accident (e.g. struck by moving vehicle, or aggression):

  • Total number of serious accidents yearly reported to the Dutch labour inspectorate.
  • Most important activities that a person carried out when the accident happened or other important factors (e.g. type of tools, machines, material used).
  • Direct causes, that indicate where it went wrong, meaning which barrier failed.
    An accident happens when one or more barriers fail. A barrier is an essential safety function, which can prevent an accident to happen or mitigate the consequences. A barrier can be an object, but also a condition or state. Examples are physical guarding of a machine, prevention of entering the danger zone, emergency response, driving ability, etc.
    Each type of accident has specific barriers, but they all have four modes of failing and the same underlying causes.
    When a barrier failed, this means that:
    • The barrier was not present.
    • The barrier was not used,  used incorrect or only partially.
    • The barrier was not maintained according to its intended safety function.
    • Supervision on the provision, use, or maintenance of the barrier did not exist.
  • Underlying causes, that indicate how and why it did go wrong. These are divided into two groups:
    • Failing tasks (acts that have to be performed to keep the barrier in place): provide, use, maintain, monitor.
    • Failing management delivery systems: The tasks can fail when management delivers insufficient means or motives,  8 factors are distinguished:
      • Plans and Procedures (such as tasks lists, manuals, maintenance schemes, written work instructions, etc.).
      • Availability of suitable people and time.
      • Competence (knowledge and skills of the workers carrying out their tasks).
      • Communication/collaboration (internal communication, meetings, phones, etc.).
      • Motivation/awareness/ alertness for safety.
      • Conflict resolution (handling of conflicting goals, such as safety and other company objectives).
      • Ergonomics (the fit between men and machine/material).
      • Equipment (sufficient relevant materials, tools and spares of good quality.