Business processes support the design and implementation of software as workflows of local and inter-organization activities. Tools provide the business process designer with modelling and execution facilities, but they barely provide formal analysis techniques. When one makes a process evolve, for example by refactoring it or by adding new features in it, it is important to be able to check whether, and how, this process has changed, and possibly correct evolution flaws. To reach this objective, we first present a model transformation from the BPMN standard notation to the LNT process algebra and LTS formal models. We then propose a set of relations for comparing business processes at the formal model level. With reference to related work, we propose a richer set of comparison primitives supporting renaming, refinement, property and context-awareness. We also support BPMN processes containing unbalanced structures among gateways. In order to make the checking of evolution convenient for business process designers, we have implemented tool support for our approach as a web application.

©2017 IEEE. This is an author produced version of a paper published in Proceedings of 25th Mediterranean Conference on Control and Automation. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works. Uploaded in accordance with the publisher's self-archiving policy.eprints@whiterose.ac.uk https://eprints.whiterose.ac.uk/ Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher's website. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request.Steady state evaluation of distributed secondary frequency control strategies for microgrids in the presence of clock drifts* Abstract-Secondary frequency control, i.e., the task of restoring the network frequency to its nominal value following a disturbance, is an important control objective in microgrids. In the present paper, we compare distributed secondary control strategies with regard to their behaviour under the explicit consideration of clock drifts. In particular we show that, if not considered in the tuning procedure, the presence of clock drifts may impair an accurate frequency restoration and power sharing. As a consequence, we derive tuning criteria such that zero steady state frequency deviation and power sharing is achieved even in the presence of clock drifts. Furthermore, the effects of clock drifts of the individual inverters on the different control strategies are discussed analytically and in a numerical case study.