Healthcare is a data-intensive domain, once a considerable volume of data is daily to monitoring patients, managing clinical research, producing medical records, and processing medical insurance claims. While the focus of applications of blockchain in practice has been to build distributed ledgers involving virtual tokens, the impetus of this emerging technology has now extended to the medical domain. With the increased popularity, it is crucial to study how this technology accompanied with a system for smart contracts can support and challenge the healthcare domain for all interrelated actors (patients, physicians, insurance companies, regulators) and involved assets (e.g. patients' data, physician's data, equipment's and drug's supply chain, etc.). The contributions of this paper are the following: (i) report the results of a systematic literature review conducted to identify, extract, evaluate and synthesize the studies on the symbiosis of blockchain in healthcare; (ii) summarize and categorize existing benefits/challenges on incorporating blockchain in healthcare domain; (iii) provide a framework that will facilitate new research activities; and (iv) establish the state of evidence with in-depth assessment.

Software architectures have been recognized as the backbone to the success of any software system. In addition, they are responsible to aggregate quality attributes, such as interoperability, dependability, and maintainability, to these systems. In parallel, currently, a new class of complex software systems has emerged, referred as Systems of Systems (SoS), resulting from a number of operationally and managerially independent software systems working together to fulfill a mission that none system alone could provide. Considering their complexity, the development of SoS has demanded special attention to their software architectures. In this scenario, the description of such architectures, i.e., the way that these architectures are represented/documented, becomes quite important as it can improve communication as well as evaluation and maintenance of these architectures. Despite its relevance, there is still no complete panorama about architectural descriptions of SoS. The main contribution of this paper is to present results of a Systematic Literature Review (SLR) on how SoS software architectures have been described. As main result, there are already important contributions in that direction; however, there is a lack of consensus on how better dealing with these descriptions. We conclude this paper with directions on how a consensus could be achieved and which aspects of the SoS architectural descriptions require further investigation.

Background Systems-of-systems (SoS) are alliances of independent and interoperable software-intensive systems. SoS often support critical domains, being required to exhibit a reliable operation, specially because people’s safety relies on their services. In this direction, simulations enable the validation of different operational scenarios in a controlled environment, allowing a benchmarking of its response as well as revealing possible breaches that could lead to failures. However, simulations are traditionally manual, demanding a high level of human intervention, being costly and error-prone. A stimuli generator could aid in by continuously providing data to trigger a SoS simulation and maintaining its operation. Methods We established a model-based approach termed Stimuli-SoS to support the creation of stimuli generators to be used in SoS simulations. Stimuli-SoS uses software architecture descriptions for automating the creation of such generators. Specifically, this approach transforms SoSADL, a formal architectural description language for SoS, into dynamic models expressed in DEVS, a simulation formalism. We carried out a case study in which Stimuli-SoS was used to automatically produce stimuli generators for a simulation of a flood monitoring SoS. Results We run simulations of a SoS architectural configuration with 69 constituent systems, i.e., 42 sensors, 9 crowdsourcing systems, and 18 drones. Stimuli generators were automatically generated for each type of constituent. These stimuli generators were capable of receiving the input data from the database and generating the expected stimuli for the constituents, allowing to simulate constituent systems interoperations into the flood monitoring SoS. Using Stimuli-SoS, we simulated 38 days of flood monitoring in little more than 6 h. Stimuli generators correctly forwarded data to the simulation, which was able to reproduce 29 flood alerts triggered by the SoS during a flooding event. In particular, Stimuli-SoS is almost 65 times more productive than a manual approach to producing data for the same type of simulation. Conclusions Our approach succeeded in automatically deriving a functional stimuli generator that can reproduce environmental conditions for simulating a SoS. In particular, we presented new contributions regarding productivity and automation for the use of a model-based approach in SoS engineering.

Healthcare is a data-intensive domain, once a considerable amount of data is daily produced due to monitoring patients, managing identities, producing medical records and processing medical insurance claims. Hence, security, besides other quality requirements, is prominent to preserve the confidentiality and integrity of such data. Blockchain technology has received attention as a mean to support secure transactions and records, including in the healthcare domain. The main contribution of this paper is providing preliminary results of an investigation on the recent literature on how the inherent characteristics of blockchain can enhance or hinder particular quality requirements in healthcare systems. We provide a preliminary analysis of five essential quality requirements for healthcare domain, besides pointing for advances that must still be achieved.