The Holt–Winters models are one of the most popular forecasting algorithms. As well-known, these models are recursive and thus, an initialization value is needed to feed the model, being that a proper initialization of the Holt–Winters models is crucial for obtaining a good accuracy of the predictions. Moreover, the introduction of multiple seasonal Holt–Winters models requires a new development of methods for seed initialization and obtaining initial values. This work proposes new initialization methods based on the adaptation of the traditional methods developed for a single seasonality in order to include multiple seasonalities. Thus, new methods to initialize the level, trend, and seasonality in multiple seasonal Holt–Winters models are presented. These new methods are tested with an application for electricity demand in Spain and analyzed for their impact on the accuracy of forecasts. As a consequence of the analysis carried out, which initialization method to use for the level, trend, and seasonality in multiple seasonal Holt–Winters models with an additive and multiplicative trend is provided.

Business progress and human development are linked to the efficient management of energy resources. The research in this paper contributes to the generalized application of good practices that reduce the vulnerability of companies. The research focuses on energy efficiency through comprehensive management systems (CMS), and “thought based on risks and opportunities”, considering the discussion about the revision of ISO 50001:2018, the basic approach of the model and the route to implement CMS for quality, safety and health in the workplace, environmental management, energy efficiency, and other risk components. This implementation route, with the acronym CMS QHSE3+, places special emphasis on the functions of strategic planning, operational and risk management, and controls, as well as on deliverables and references to examples, templates, standards, and documents, to facilitate its application general in small and medium enterprises and in the management of energy efficiency.