Definitions

Every day, experts at AWS assist customers in architecting systems to take advantage of best practices in the cloud. We work with you on making architectural trade-offs as your designs evolve. As you deploy these systems into live environments, we learn how well these systems perform and the consequences of those trade-offs.

Based on what we have learned, we have created the AWS Well-Architected Framework, which provides a consistent set of best practices for customers and partners to evaluate architectures, and provides a set of questions you can use to evaluate how well an architecture is aligned to AWS best practices.

The AWS Well-Architected Framework is based on six pillars — operational excellence, security, reliability, performance efficiency, cost optimization, and sustainability.

Table 1. The pillars of the AWS Well-Architected Framework

Name	Description
Operational excellence	The ability to support development and run workloads effectively, gain insight into their operations, and to continuously improve supporting processes and procedures to deliver business value.
Security	The security pillar describes how to take advantage of cloud technologies to protect data, systems, and assets in a way that can improve your security posture.
Reliability	The reliability pillar encompasses the ability of a workload to perform its intended function correctly and consistently when it’s expected to. This includes the ability to operate and test the workload through its total lifecycle. This paper provides in-depth, best practice guidance for implementing reliable workloads on AWS.
Performance efficiency	The ability to use computing resources efficiently to meet system requirements, and to maintain that efficiency as demand changes and technologies evolve.
Cost optimization	The ability to run systems to deliver business value at the lowest price point.
Sustainability	The ability to continually improve sustainability impacts by reducing energy consumption and increasing efficiency across all components of a workload by maximizing the benefits from the provisioned resources and minimizing the total resources required.

In the AWS Well-Architected Framework, we use these terms:

• A component is the code, configuration, and AWS Resources that together deliver against a requirement. A component is often the unit of technical ownership, and is decoupled from other components.

• The term workload is used to identify a set of components that together deliver business value. A workload is usually the level of detail that business and technology leaders communicate about.

• We think about architecture as being how components work together in a workload. How components communicate and interact is often the focus of architecture diagrams.

• Milestones mark key changes in your architecture as it evolves throughout the product lifecycle (design, implementation, testing, go live, and in production).

• Within an organization the technology portfolio is the collection of workloads that are required for the business to operate.

• The level of effort is categorizing the amount of time, effort, and complexity a task requires for implementation. Each organization needs to consider the size and expertise of the team and the complexity of the workload for additional context to properly categorize the level of effort for the organization.

  • High: The work might take multiple weeks or multiple months. This could be broken out into multiple stories, releases, and tasks.

  • Medium: The work might take multiple days or multiple weeks. This could be broken out into multiple releases and tasks.

  • Low: The work might take multiple hours or multiple days. This could be broken out into multiple tasks.

When architecting workloads, you make trade-offs between pillars based on your business context. These business decisions can drive your engineering priorities. You might optimize to improve sustainability impact and reduce cost at the expense of reliability in development environments, or, for mission-critical solutions, you might optimize reliability with increased costs and sustainability impact. In ecommerce solutions, performance can affect revenue and customer propensity to buy. Security and operational excellence are generally not traded-off against the other pillars.