To reduce the number of factors considered for the survey, we used the following criteria to exclude factors. Therefore we reduced the factors used in the survey from 76 to 45.
We excluded intermediate factors merely serving as aggregators, that means factors which combine their subfactors to an aggregated factor. This applied to the following factors:
- Secrets management
- Access restriction
- Service-orientation
- Limited functional scope
- Isolated state
- Loose coupling
- Standardization
- Automated monitoring
- Service independence
- Operation outsourcing
- Replication
- Resource predictability
- Configuration management
- Distribution
- Seamless upgrades
- Autonomous fault handling
- Communication indirection
We excluded factors which are less specific to cloud computing, that means applying also to different kinds of applications. This applied to the following factors:
- Data encryption in transit
- Isolated secrets
- Least-privileged access
- Limited endpoint scope
- Component similarity
- Low coupling
- Functional decentralization
- Sparsity
- Cost variability
- Isolated configuration
- Standardized self-contained deployment unit
- Guarded ingress
- Invocation timeouts