Specification of requirements on the functional behaviour of system components is a central concern for the overall safety of software systems. Therefore, the methodology used for analysing failure modes resulting from requirement violations is of utmost importance to safety within the automotive industry. ISO 26262 is a standard for functional safety within the automotive industry, in which the concept of Automotive Safety Integrity Levels (ASILs) is defined. ASILs are assigned to requirements, and represents the risk associated with violating said requirements. As redundancy is introduced into systems, requirements are broken down and may have their ASILs lowered through ASIL decomposition. This paper examines ASIL decomposition as defined in ISO 26262, and identifies reasons for why the suggested pattern is insufficient for common use cases within the automotive industry. The paper also proposes an improved pattern, which is applied to an industrial case and analysed for its implications on system safety.