Training operators to efficiently operate critical systems is a cumbersome and costly activity. A training program aims at modifying operators’ knowledge and skills about the system they will operate. The design, implementation and evaluation of a ‘good’ training program is a complex activity that requires involving multi-disciplinary work from multiple stakeholders. This paper proposes the combined use of task descriptions and augmented reality (AR) technologies to support training activities both for trainees and instructors. AR interactions offer the unique benefit of bringing together the cyber and the physical aspects of an aircraft cockpit, thus providing support to training in this context that cannot be achieved by software tutoring systems. On the instructor side, the LeaFT-MixeR system supports the systematic coverage of planed tasks as well as the constant monitoring of trainee performance. On the trainee side, LeaFT-MixeR provides real-time AR information supporting the identification of objects with which to interact, in order to perform the planned task. The paper presents the engineering principles and their implementation to bring together AR technologies and tool-supported task models. We show how these principles are embedded in LeaFT-MixeR system as well as its application to the training of flight procedures in aircraft cockpits.

The building workers sector is one of the most challenging sectors for Human Resources (HR) management. In this work, we propose a solution relying on Blockchain technology and present the design of a Blockchain-Oriented Software system conceived for managing the building workers sector with a focus on workers' safety, and it is guided by sustainable and Agile Methodologies in software design. The proposed approach takes advantage of different features of the Blockchain technology and provides transparency for labor inspectors, grants data integrity and immutability, relies on tamper-proof time stamps for any recorded activity, allows the implementation of Smart Contracts where clauses are automatically respected without the need of a trusted control authority, acknowledges the legal requirements in the field, including the possibility of creating an Operational Safety Plans, which construction companies have to provide, and finally implements the creation of vacant job positions that workers can find and apply to. In order to achieve these goals, we adopt the Blockchain-Oriented Software Engineering (BOSE) methodology to design Blockchain software applications and apply an Agile methodology centered on Blockchain Software development (called ABCDE) for the design and development of the decentralized application. Such a methodology allows us to center the software development around the actors of the system in the specific domain, such as Building Workers, Construction Companies, Labor Inspectors, and so on. In addition, we rely on the software sustainability analysis, based on the five dimensions of sustainability, to evaluate the approach and to avoid mistakes in the system development. We design system elements with specific diagrams, and we divided our system in the on-chain and the out-of-chain components. The implementation of the system, done by using Ethereum and the ERC721 standard, allows us to improve some aspect of the design, to know the deployment and usage costs, and to evaluate the effect of the user interface. Finally, we discuss the effects of our system and its sustainability, and we provide a comparison of our system with a similar per aims but centralized system.