Tool Safety Manual

A Tool Safety Manual (TSM) is a vital document that complements the use of a software tool. It serves as a guide for development teams, outlining how to use a specific software tool safely and correctly within a safety-critical development process. It goes beyond a standard user manual by focusing specifically on the aspects relevant to achieving and maintaining functional safety compliance.

Software tools are fundamental instruments used throughout the safety lifecycle to develop systems. While the tools themselves do not execute in the final product, errors introduced by a tool can directly compromise the safety and compliance of the final system.

A Tool Safety Manual is essential because it documents the specific assumptions, conditions, configurations, and procedures under which a tool has been deemed suitable (often through qualification) for use in a safety-critical context. It helps prevent misuse that could inadvertently introduce hazards or audit findings.

A Tool Safety Manual in the automotive field is the complementary outcome of the process defined in standards like ISO 26262 (Part 8, Clause 11). Tool qualification is the process of demonstrating that a software tool can be confidently used in the development of safety-related items or elements. Based on the tool's potential impact on the final product's safety (its Tool Confidence Level, TCL), a specific qualification method might be required.

For a qualified tool, extensive validation work has been done upfront, proving its reliability for specific uses. This means less operational burden is placed on the end user, and the Tool Safety Manual can be more concise and user-friendly, mainly listing validated use cases, constraints, and any remaining limitations.

In contrast, for a tool that has not been qualified, the burden shifts to the developer. The Tool Safety Manual for such a tool must describe potentially extensive manual procedures such as additional thorough checks, manual reviews, or compensating verification steps that the user must perform to ensure safety, making its safe application significantly more effort-intensive and risk-prone.