Functional Safety: Where Manufacturers Should Start

21 Oct 2026

A Framework for Ensuring Systems Behave Predictably When Failures Occur

As modern products increasingly rely on electronic controls, sensors, and embedded software, the topic of Functional Safety appears more frequently during product certification. Many manufacturers first encounter Functional Safety requirements when an applicable product standard calls for additional evaluation of control systems or safety-related software. At that point, a common question arises: Where should we start?

From an engineering perspective, Functional Safety is not a separate discipline. In most cases, manufacturers already implement protective features in their designs. Functional Safety simply provides a structured way to design and verify that those protections continue to operate correctly when faults occur.

This framework is defined by internationally recognized standards such as IEC 61508, with sector-specific applications including IEC 62061 and ISO 13849 for machinery. These standards establish how safety-related control systems should be designed, implemented, and validated to ensure reliable operation under fault conditions.

Start with Identifying Safety Functions

Functional Safety begins with the same foundation as any safety engineering process: understanding hazards and risks. From a certification perspective, Functional Safety requirements typically arise from three primary sources:

1. Results of a risk assessment
2. Requirements in the applicable product standard
3. Findings from failure mode analysis

A risk assessment is typically the starting point, as it identifies conditions that could lead to injury or damage. This includes consideration of foreseeable misuse, environmental conditions, and operational scenarios across the full product lifecycle, from installation and operation to maintenance and end-of-life handling.

Furthermore, many end-product standards require functional safety evaluation for some of the functions provided in the product and specify their required safety rating. These requirements are intended to verify that the system behaves safely during normal operation and abnormal conditions.

The results of this analysis often identify the safety functions within the system that are responsible for preventing dangerous conditions and determine their required safety rating (SIL, PL, ASIL, etc.). Safety ratings vary based on the application Functional Safety standard; IEC 61508 uses Safety Integrity Level (SIL); ISO 13849 uses Performance Level (PL), ISO 26262 uses Automative Safety Integrity Level (ASIL); these are all measures of how reliable a safety function must be to reduce risk to an acceptable level.

Examples of safety functions include:

• Shutting down a heater when temperatures exceed safe limits
• Shutting down a motor if it is stalled or overloaded
• Closing a gas valve when ignition fails
• Limiting battery charging conditions to prevent overheating

Why Early Planning Matters

Many manufacturers first encounter Functional Safety during certification testing. At that stage, it may become clear that certain control functions require additional evaluation. Addressing these requirements late in development can lead to redesigning work or extended certification timelines.

When Functional Safety considerations are addressed earlier in the design process, manufacturers can:

• Identify safety-related functions early
• Design control systems with appropriate reliability
• Avoid unexpected certification delays

The practical takeaway for this concept is that Functional Safety does not have to be complicated. As mentioned, a practical starting point usually includes:

• Performing a risk assessment and reviewing the applicable product standard to identify hazards
• Determining which system functions prevent those hazards (safety functions)
• Determining required reliability of the safety functions to control these hazards and evaluating how those systems respond to faults

When these steps are integrated into product development, Functional Safety becomes a manageable engineering activity rather than a certification obstacle.

Conclusion

Functional Safety provides a framework for ensuring systems behave predictably when failures occur. When manufacturers identify safety functions early and design with these requirements in mind, Functional Safety becomes a manageable engineering activity rather than a certification obstacle.

In practice, the question “Where do we start with Functional Safety?” usually has a straightforward answer:

Start with the hazards, identify the safety functions that control them, and evaluate those functions early in the design process to ensure they achieve the required level of reliability.