---
category: [Administration & Integrations, Administration & Integrations/Custom Integrations & Apps, Platform and Product Extensions, Platform and Product Extensions/Workday Extend, Platform and Product Extensions/Integration]
keyword: [Extend, Model Components, promote]
nav: wcp_docs
parent_url: /wcp_docs/
title: >- 
  Concept: Extend Apps with Model Components
layout: subsection
---

## <a id="section_w4x_s4q_wpb"></a>Install Apps with Model Components

You can only install an app with model components on an Implementation, Sandbox, or Production tenant after the model components of the app deploy to the tenant as part of Workday's Weekly Service Update.

As a consequence, you must promote your app before a weekly deadline for new or updated model components to deploy to your Workday tenant. To find your promotion deadline, see [Reference: Promotion Deadlines for Extend Apps with Model Components](/wcp_docs/giw1660842903762.html).

<b>Note:</b> In order for an app with model components to be available on your Production tenant when your Workday implementation goes live for the first time, promote your app to Production 1 week before Workday creates your Production tenant from your Gold tenant. Otherwise, the app won't be available to install on your Production tenant until you promote the app to Production .

## <a id="section_nl3_jpq_wpb"></a>Update Apps with Model Components

When you update an app with model components, you can:

-   Add new model components.
-   Add new fields to existing model components.
-   Add new security domains to business objects.
-   Add new security domains to individual fields on business objects.
-   Update page routes in business processes.


<b>Note:</b> You can't remove model components that deployed in a previous version of the app.

After you update an app to the next version, you don't need to reinstall the app.

When you promote the updated app to your Implementation, Sandbox, or Production tenant, the model components deploy to the tenant as part of Workday's Weekly Service Update.

As a consequence, you must promote your app before a weekly deadline for new or updated model components to deploy to your Workday tenant. To find your promotion deadline, see [Reference: Promotion Deadlines for Apps with Model Components](/wcp_docs/giw1660842903762.html).

<b>Note:</b> Workday makes updates to your app available to your tenant immediately, except when model components are already queued to deploy to the tenant during an upcoming Weekly Service Update. In this case, Workday makes updates to your app available to your tenant after the Weekly Service Update completes.

### Related Information

[Concept: Workday Extend App Lifecycle](/wcp_docs/cjw1620248412279.html)

[Reference: Allowed Updates After App Promotion](/wcp_docs/haf1635898070118.html)

[Tutorial: Extend Model Components Learning Program](https://wd5.myworkday.com/workday/learning/program/6a1b5a71c93c100094b72fead10f0000?type=2d29754fdb8e100008b50ff6bc94003b)

[Tutorial: Getting Started with Model Components](https://wd5.myworkday.com/workday/learning/course/84f2dcc34eff01f6facdbc20612cd98b?type=9882927d138b100019b928e75843018d)