# Measure, enforce, and evolve


Metrics are necessary to identify improvements in this process, and to evolve the governance. Are measures and KPIs improving over time? Are the envisioned outcomes being realized? Are resources been allocated properly? Is the enforcement mechanism too strong, or weak?

Examples of tagging KPIs include the following:
+ Tag coverage rate (per tag key)
+ Tag coverage rate (aggregate)
+ Percent of total spend tagged
+ Percent non-allocable spend (resources that were not tagged)

Examples of outcome-based KPIs include the following:
+ Number of resources terminated
+ Amount of money saved
+ Time saved (for example, by automating financial allocations)

## Proactive enforcement


For proactive enforcement, you can determine which resources must be tagged. Then you can apply tag policies or service control policies (SCPs) using the AWS Organizations console.

A tag policy is applied to an organizational unit (OU) or a target account. For example, a policy can require a pre-defined `tag_value` for Amazon Elastic Compute Cloud (Amazon EC2) instances and volumes. In this example, if someone tries to launch an EC2 instance with a value different from `ABC123` or `ABC1234` (assigned for `tag_value`), an error message will be returned, because the EC2 instance isn’t respecting the tag policy.

SCPs are also applied to an OU or a target account. For example, a SCP can require a predefined `tag_key` forAmazon EC2 instances and volumes. In this example, if someone tries to launch an EC2 instance without the requested `tag_key` `cost-center-id`, an error message will be returned.

## Reactive enforcement


Reactive governance is used to find resources that are not properly tagged. You can use tools such as the Resource Groups Tagging API, AWS Config rules, and Tag Editor. For example, AWS Config rules can use a managed rule `required-tags` to verify that every asset has been correctly tagged with a tag named `cost-center-id` with allowed values `ABC123` or `ABC1234`. Any asset identified not having the required tag or the required values in the tag will be noncompliant.

To fix existing, noncompliant resources, we recommend the following solution:
+ [GorillaStack Auto Tag](https://github.com/gorillastack/auto-tag)

## Cost Explorer


After tagging the resources, you can see them by using [AWS Cost Explorer](https://aws.amazon.com/aws-cost-management/aws-cost-explorer/). It’s an interface that helps you to visualize and manage your AWS costs and usage over time by creating custom reports that analyze cost and usage data. On the AWS Management Console, open the Cost Explorer console. Then use the **Tag** filter to visualize the cost and usage by tag, according to the tagging dictionary tag template that was created before. For example, you can filter by project or by team.

To create Cost and Usage Reports that you can use with Amazon Quick Sight or Amazon Athena, see [Creating Cost and Usage Reports](https://docs.aws.amazon.com/cur/latest/userguide/cur-create.html).

## Amazon Quick Sight


You can visualize your AWS cost and usage by using [Amazon Quick Sight](https://aws.amazon.com/quicksight/). Amazon Quick Sight is a cloud business analytics service to build visualizations, analysis, and quickly get business insights from data.

To analyze AWS Cost and Usage Reports with Amazon Quick Sight, see [How do I ingest and visualize the AWS Cost and Usage Report (CUR) into Amazon Quick?](https://aws.amazon.com/premiumsupport/knowledge-center/quicksight-cost-usage-report/)

## Amazon Athena


Amazon Athena is another way to analyze the data from your AWS Cost and Usage Reports. Amazon Athena is a serverless query service that supports standard SQL queries. Using Amazon Athena, you can query the data from Cost and Usage Reports stored in Amazon Simple Storage Service (Amazon S3).

To set up Amazon Athena for analyzing Cost and Usage Reports, see [Querying Cost and Usage Reports using Amazon Athena](https://docs.aws.amazon.com/cur/latest/userguide/cur-query-athena.html).