Cause and Effect

Cause & Effect (C&E) diagrams show the relationship between sensor inputs and their required outputs. C&Es provide a clear and concise visual representation in tabular form, allowing users to quickly and easily view multiple functions within a process area or logic solver. They are commonly used as functional specifications for PLC-based programs, such as a Safety Requirement Specification (SRS) for a Safety Instrumented System (SIS). As such, they are of critical importance to successful implementation of the Safety Instrumented Functions (SIFs) in any functional safety project. While C&Es are not directly required by the ANSI/ISA-61511-2-2018 / IEC 61511-2:2016 standard, they are often included as an extension of the SRS, making them a part of the Safety Lifecycle.

aeSolutions C&E diagrams use standard industry terms or terms that the client has clearly defined and are named, formatted, tracked, issued, controlled, and checked per aeSolutions company procedures unless superseded by specific client requirements. Our C&E templates have been developed from many years of experience to optimize ease-of-use for configuration, testing, operator training and turnover effectiveness. In cases where the functional complexity exceeds the capacity of C&Es, our staff is capable of selecting the most efficient alternate format.