Many small and medium sized enterprises (SMEs) are obliged to adopt a Safety Managements System (SMS) by the Directive 2012/18/EU for the control of Major Accident Hazards (Seveso III). The difficulties of implementing an SMS within a small sized work organization are well known by practitioners, including inspectors and auditors and have been discussed in many recent papers. In the present paper is discussed a new method, based on the bowtie model, to build an easy and effective SMS. The very core of this method is a "safety net model", which is able to connect in a network all the tangible and intangible elements of safety, including equipment, operating instructions, procedures and safety documents. This safety model has been used as the core of a smart application, the strength of which is the workers' contribution. The application allows the users to build step by step an SMS. It starts from a first version based just on regulations and standard codes (version 0), then it integrates internal knowledge through the bowtie paradigm (version 1). Near misses' discussion is used to transfer actual workers' experience into the system, to get intermediate improvement of the SMS (version 1.x). At the end audit may be used to a major release of the SMS (version 2). The full cycle has been tested at two small Seveso establishments: a galvanic plant and small glue manufacturer. (C) 2014 Elsevier Ltd. All rights reserved.