The quality factors support the functional requirements for smart cities. An outline of the quality factors is in the below:
- Interoperability: Smart cities need to operate between heterogeneous components and systems.
- Authentication and Authorization
- Availability: Smart city systems require high availability in service provisioning, data management, communication, and sensing.
- Confidentiality/Trust: Stakeholders and users require having confidence that the smart city systems/devices process and handle the data according their needs and rights.
- Scalability: A smart city system needs to be scalable to respond effectively when the system increases in the volume.
- Privacy: Owners and users require the protection of their personal information.
- Real-time: Smart city systems can require real-time sensing and monitoring, intelligent processing and big data online analytics.
- The reliability is directly related to the consistent behaviour of the systems.
- Context-aware: Devices, services, and systems require being able to monitor its own environment in which they operate and events within that environment.
- Flexibility: The smart city systems require providing different functionalities, depending on user needs and context.
- Integrity: smart cities need to make heterogeneous physical objects accessible on a large scale and to integrate them with the digital world.
- Adaptability: Smart city systems require providing high availability in service provisioning, data management, communication, and sensing.
- Extensibility: Smart city systems need to add new functionalities, components, services, and applications to the platform anytime.
- Configurability: Smart city systems need to allow (re)configuration of their components.
- Service-based: Smart city systems require offering services and adding new functionalities easily in a flexible environment for application development.
- Security: Security needs to be considered during capturing, storing, transferring, aggregating and processing the data of things, as well as to the provision of services in the city.
According to Kakarontzas et al. (2014), the most prominent quality drivers are in the order of importance: 1) Interoperability; 2) Usability; 3) Authentication and Authorization; 4) Availability; 5) Recoverability; 6) Maintainability; and 7) Confidentiality. Kakarontzas et al. (2014) revealed the need to provide interoperability, different access mechanisms (usability), and different authorization mechanisms (security). As well they stressed the need to recoverability regarding the reliability quality property. The services should be able to recover rather gracefully and quickly in cases of failures.
Likewise, as Bastidas et al. (2018) summarised, the key non-functional requirements of smart city systems which capture quality support or performance characteristics as follows: 1) Scalability, 2) Security, 3) Trus, 4) Privacy, 5) Availability, 6) Reliability, 7) Real-time, 8) Interoperability, 9) Context-aware, 10) Flexibility, 11) Heterogeneity,12) Integrity, 13) Adaptability, 14) Extensibility, 15) Configurability, and 16) Service-based
- Privacy protection should be considered during capturing, transferring, storing, validating and processing data of devices (Sicari et al., 2015).
- Bastidas, V., Helfert, M. and Bezbradica, M., 2018, January. A Requirements Framework for the Design of Smart City Reference Architectures. In Proceedings of the 51st Hawaii International Conference on System Sciences.
- Kakarontzas, G., Anthopoulos, L., Chatzakou, D. and Vakali, A., 2014, August. A conceptual enterprise architecture framework for smart cities: A survey based approach. In e-Business (ICE-B), 2014 11th International Conference on (pp. 47-54). IEEE.
- Sicari, S., Rizzardi, A., Grieco, L.A. and Coen-Porisini, A., 2015. Security, privacy and trust in Internet of Things: The road ahead. Computer networks, 76, pp.146-164.