The Optimizely framework is a set of NuGet packages that are part of a web application, which you can host locally or in the cloud. You upgrade Optimizely through Visual Studio and the NuGet package manager. New releases are available weekly to keep your solutions up to date.
Note
Looking to upgrade to ASP.NET Core and CMS 12? See [Why upgrade to Optimizely Content Management System (CMS 12)?](🔗).
## Upgrade steps
Optimizely products consist of a main NuGet package with dependencies to other required packages. When updating, you only have to select the main package.
Optimizely release packages are published to the [Optimizely NuGet feed](🔗). You can download and install release packages from here via the Package Manager or command prompt in **Visual Studio**.
If not already done, add the Optimizely NuGet feed to the NuGet package manager in Visual Studio, see [Installing a sample site](🔗) how to do this.
Right-click on **References **in your project, and select **Manage NuGet Packages**.
Select **Updates **> **Episerver **and click **Update **for the **EPiServer.Cms.Web **package. This adds the latest changes to your project.

Compile your solution and start the website. You may see a system application exception caused by conflicting application and database schema versions, as each database schema version targets a specific Optimizely version.
In the Visual Studio Package Manager Console, run the command `
update-epidatabase
`.
Reload the website, and verify that you can log in to the user interface.
## Release management
### Semantic versioning
Optimizely follows [semantic versioning](🔗). Release packages are numbered with a three-digit series, for example 11.12.0.
When the first digit is bumped, the release is called _a major version_. Major versions are releases that have some breaking changes. And by breaking changes, we mean that a developer may have to change something in their code before they can upgrade.
When the second digit is bumped, the release is called _a minor version_. A minor release has some new features.
When the third digit is bumped, the release is _a bugfix version_ and only contains bug fixes. It does not contain any new functionality.
**Example of releases:**
**10.0.0** (breaking changes) -> **10.1.0** (contains same functionality as 10.0.0 plus some new functionality) -> **10.1.1** (contains same functionality as 10.1.0 plus some bug fixes) -> **10.2.0** (same functionality as 10.1.1 plus new functionality) -> ... -> **10.8.2** (contains all features and bug fixes from previous versions plus new bug fixes) -> **11.0.0** (breaking changes).
### Continuous releases
Instead of doing large releases once or twice a year, Optimizely uses a continuous release process with short development and test cycles, and release of new versions every week or fortnight.
This way each release only contains a limited number of features and bug fixes, speeding up the time to market and making upgrading smoother. Each new release package is _cumulative_, which means that it contains all previous updates as well.
As a developer, you decide how often you want to upgrade, but the more often you upgrade, the smoother it is.
### How frequent should you upgrade?
The upgrade frequency of the Optimizely platform entirely up to you and is probably driven by specific feature and fixes that you want or need. Update packages are cumulative, but the longer you wait between upgrades, the more likely it is that bigger changes were introduced, which may result in a larger upgrade project.
If you find and verify an issue in the Optimizely platform, you should do the following:
Upgrade your staging environment to the latest minor version within the same major version to see if the issue was resolved in a later minor version.
If the issue is not resolved, browse the [release notes](🔗) and see if the issue was resolved in a later major version. If so, read the change log up to that version and consider whether an upgrade is a reasonable effort. Major releases often have their own documentation, such as [Upgrade to Optimizely Content Management System (CMS 12)](🔗) for example.
If you consider the upgrade too big or the issue wasn't resolved in any update, contact [customer support](🔗) for a possible workaround.
If customer support does not have a workaround, you may request a patch version within your current major version. Your request will be triaged by the Optimizely development team with the following criteria for approving or declining a patch version:
Actual impact for the customer.
Identified regression issues for the patch. If the patch version is declined, the issue will be treated as a bug that will be prioritized for the next update.
See also the blog: [Continuous Release Process](🔗) by Per Ivansson on June 19, 2014.
### Release information
[**Optimizely release notes**](🔗) The Optimizely development teams use a software tracking system to track work items. When a feature or bug fix is in test, it is displayed in the **Optimizely release notes** feed with the status '_Soon to be released_''. As soon as the feature or bug fix is approved and released, it is associated with a specific release and the status is changed to a release date. Use the release notes to see details about what is included in a specific package version for a product. You can also use the filters in the release notes feed to create a list of, for example, all new user interface features that have been released during the last six months.
[**Optimizely updates**](🔗) Once a week, all release packages that are ready for release are published to the Optimizely NuGet feed. At the same time, an update summarizing the weekly release information is published to the **Optimizely release update** feed. Use the weekly updates as an overview to browse updates and decide when to upgrade a solution.
### Beta features
To quickly get access to new features that are being developed, you can install **Beta features**, see [Beta features](🔗) for more information on how to work with these.
## Related topics
[Why upgrade to Optimizely Content Management System (CMS 12)?](🔗)
[Upgrade to ASP.NET Core](🔗)
[Upgrade Assistant](🔗)