Sometimes, when I'm doing a CRM presentation to my customers, I love to say them that CRM is a platform, not only an application.
Microsoft CRM can be totally customized and extended with new custom applications based on its framework and you can build your own new functionality that meets your business needs directly using the CRM platform.
There's a recent post by Arash Ghanaie that talks about it and here I want to put in evidence the key parts:
This diagram simply depicts typical components that you see in a business application. How can you use the CRM platform?
1) Targeted users: CRM platform provides an extensive range of tools, APIs and UIs to satisfy the need of different users who interact with the system.
2) User Interface components: CRM UI, including the main application and forms are customizable. You can use simple tools to customize the navigation structure and form layouts as well as the ability to include client side business logic(e.g. validation) through scripting languages and client events.
3) Security: CRM provides a rich security model based on roles and privileges that allows you to easily customize and control the access to your data and process assets, based on your need. Customization of security roles and privileges are accessible through UI tools or APIs.
4) Operation Management: administration tools and APIs allows you fully maintain and manage the lifecycle of your business application that is built on top of CRM platform
5) Communication: CRM platform is designed based on a message oriented communication architecture. Any custom application built on top of our platform will use this approach to communicate with the platform and your custom business logic that you may have embeded in the platform.
6) Service Interfaces and business components: CRM platform has a set of customizable and dynamic web services APIs that allows your application to easily work with the platform operations and business entity data. The services are fully plug-able and extendable through code. The Workflow engine provides the ability to easily define custom business processes and hook them into various platform events. The Business Entity model is flexible and fully customizable through web service APIs or the UI components and tools.
7 & 8) Data storage and access: The data access provides multiple choices to access and manage data ranging from UI based query building and execution model for non-technical users to direct read from SQL format to strongly typed query building using IntelliSense in Visual Studio.
Arash has done a great resume of what could be the key points of building a complex architecture based on Microsoft CRM platform. Obviously, I'm not here to say that Microsoft CRM could be the "building block" for every application you want, but if your business needs a CRM application as part of it, consider that CRM could be the hearth of your architecture.