Requirements modelling by synthesis of deontic input-output automata

Requirements modelling helps software engineers understand a system´s required behaviour and explore alternative system designs. It also generates a formal software specification that can be used for testing, verification, and debugging. However, elaborating such models requires expertise and significant human effort. The paper aims at reducing this effort by automating an essential activity of requirements modelling which consists in deriving a machine specification satisfying a set of goals in a domain. It introduces deontic input-output automata - an extension of input-output automata with permissions and obligations - and an automated synthesis technique over this formalism to support such derivation. This technique helps modellers identifying early when a goal is not realizable in a domain and can guide the exploration of alternative models to make goals realizable. Synthesis techniques for input-output or interface automata are not adequate for requirements modelling.