A general model for specifying near periodic recurrent activities - application to home care activities

Most of human activities are repetitive. Their explicit specification is necessary for many reasons especially to prepare their planning. This specification is generally made in a calendar form (developed form) but repetitions do not appear directly. Another solution consists in making this specification in an assertional form (condensed form) where repetitions are directly expressed in natural or quasi-natural language (i.e.: every day at 8 am except Sunday). Specifications under condensed form are easier to communicate and allows making more elaborated reasoning than the developed form. We propose in this paper a general model to express almost near regular repetitions in a condensed form. The irregularities appear for at least two reasons: the activity can be strengthened over some periods, exceptions exist some days. An illustration of our model is proposed to specify home care activities.