This Guidance on Developing Safety Performance Indicators ('Guidance on SPI') was prepared to assist enterprises that wish to implement and/or review Safety Performance Indicator Programmes. The three chapters in this Guidance are designed to help enterprises better understand safety performance indicators, and how to implement SPI Programmes. Speciﬁcally, Chapter 1 provides important background information on the Guidance and on SPIs more generally including (i) a description of the target audience for this Guidance, (ii) deﬁ nitions of SPIs and related terms, and (iii) insights on the reasons for implementing an SPI Programme. Chapter 2 sets out a seven-step process for implementing an SPI Programme, along with three examples of how different types of enterprises might approach the establishment of such a Programme. These seven steps build on the experience of a number of enterprises in the UK that worked with the Health and Safety Executive to develop a practical approach for applying performance indicators. Chapter 3 provides additional support for the development of an SPI Programme by setting out a menu of possible elements (targets, outcome indicators and activities indicators). This menu is extensive in light of the different types of potentially interested enterprises, recognising that each enterprise will likely choose only a limited number of the elements to monitor its key areas of concern. Furthermore, it is understood that an enterprise may decide to implement an SPI Programme in steps, focusing ﬁ rst on only a few priority areas, and then expanding and amending its Programme as experience is gained. Annexes provide further support with an expanded explanation of metrics and a summary of targets, along with a glossary, a list of selected references and a copy of the Guiding Principles’ 'Golden Rules.'