Appunti completi di Safety Engineering and Management

Safety engineering

1. Introduction

Safety engineering is a field that focuses on ensuring systems operate safely and reliably. The discipline involves understanding process items, system analysis, reliability, and safety applications. A systems approach to engineering concepts is essential for successful safety engineering.

2. System safety engineering

System safety engineering involves defining system requirements and conducting safety analysis. This includes process units, hazard analysis, Failure Modes and Effects Analysis (FMEA), and fault tree analysis. Specialist system safety and reliability requirements also play a crucial role.

The main components of system safety engineering are:

• System requirements
• Safety analysis
• Process analysis
• Hazard analysis
• Methods

3. Human & organizational factors (HOF)

Consideration of human and organizational factors is vital in safety engineering. This includes understanding human errors and utilizing tools like the Predictive Human Error Analysis (PHEA) and the Process Error Reduction Diagram (PERD).

The basics of HOF involve:

• Human errors
• PHEA
• PERD
• Collaboration
• Reason's Swiss cheese model

4. Theory & systems of investigation analysis (MTSI)

The MTSI section covers accident investigation, root cause analysis, and tools like fault tree analysis and bow tie models. Safety management system (SMS) principles and performance indicators are also explored.

5. Occupational health & safety

Occupational health and safety (OHS) involves understanding management systems, risk management, regulations, and continuous improvement. The section also covers OHS inspection cycles and includes models, approaches, and calculations related to safety engineering.

System and safety concepts

A system can be defined as a group of interacting, interrelated, or interdependent elements forming a collective unity. A subsystem represents an element of a system that may constitute a system on its own. Systems can be composites of people, processes, and equipment integrated to perform specific operational tasks within a particular environment.

A cyber-physical system is a mechanism controlled or monitored by computer-based algorithms, tightly integrated with the internet and its users. These systems involve physical and software components that are deeply intertwined, operating on different spatial and temporal scales but interacting in various ways.

Safety refers to the degree of confidence that, under given circumstances, we are free from undergoing or causing harm or loss. It can be thought of as a characteristic of the system.

System safety is the characteristic of a system that allows it to function under predetermined conditions with an acceptable minimum of accidental loss. System safety engineering combines management and system engineering practices to evaluate and reduce safety risks within a system's operation, requiring a closed-loop process.

System safety engineering process

• Identify the hazards in a system.
• Determine the underlying causes of hazards.
• Develop control options to eliminate the hazards or mitigate their consequences.
• Verify that the controls are adequate and in place.
• Maintain the system after changes and modify further as needed.

This process involves defining objectives, system description, hazard identification, hazard analysis, periodic system review, system specification, risk evaluation, hazard controls, and verification.

Risk management

Hazard refers to everything that may impact the safety level of the system. It may cause harm or loss when interacting with the system. The life policy should be limited by the current risk homeostasis system at the corporate level. Safety and security disciplines are designed to affect the total lifecycle of a system.

Concept to operation phases

The development of a safety system includes several phases:

• Concept: Emissions analysis and preliminary design accompanied by Systematic Risk Assessment and Design Evaluation (SRADE).
• Detailed design: Critical design is conducted, resulting in detailed specifications of the system's structure and character, along with detailed drawings and calculations.
• Development: The system is constructed and tested, involving several iterations detailed in design and development phases.
• Production/construction: The product enters the manufacturing phase, where an effective system is built.
• Operation: The system is commissioned and starts to perform its intended function.