This overview presents aspects that link sleepiness and are reflected in a model. Sleepiness is a common health problem today, affecting up to one-third of the population and related to many work accidents and injuries. Traffic accidents related to sleepiness are one area that has drawn a fair amount of attention. A better general understanding of sleepiness in society, including causes of sleepiness, predictors, indicators, and the risks of being sleepy, is needed. Although sleepiness and related aspects are multidisciplinary research fields that involve business, public interests, and governmental responsibilities, a comprehensive model of sleepiness and related aspects is lacking. The purpose of this overview was related to aspects of sleepiness into a simple model, balance scale, and to describe the aspects in the proposed model, which includes sleep dept, stimulations, level of sleepiness, sleepiness indicators, circadian rhythm, and the risk of an accident. This might increase the understanding how the aspects interact and affect each other. A simple model of sleepiness and related aspects has potential to facilitate the understanding between different interests in this multidisciplinary research field.