We have discussed details about Dynamics 365 CE in all the previous chapters, but here, we are going to discuss how to upgrade to Dynamics 365 CE if you are using earlier versions of Dynamics CRM—for example, if you are working with Dynamics CRM 2011, 2013, 2015, or 2016. How you can upgrade to Dynamics 365 CE depends on which Dynamics CRM version and deployment you are using currently. For example, for online customers, it is mandatory to upgrade to the latest version after a specific duration that is determined by Microsoft. Here, there is no control over the online deployment, and you have to move to the latest version. But if you are working with an on-premises deployment, then you can choose when you want to upgrade to the new version.

If you are working with an earlier Dynamics CRM version that is closer to Dynamics 365 CE, such as Dynamics CRM 2016, then it is going to take less time compared to versions earlier than Dynamics CRM 2016. This is because there is no direct way to upgrade to Dynamics 365 CE if you are using Dynamics CRM versions earlier than 2016. For example, the following screenshot shows you the process of upgrading to Dynamics 365 CE from Dynamics CRM 2011:

This means if we are using Dynamics CRM 2011, we need to upgrade our environments one by one, starting from Dynamics CRM 2011 to Dynamics 365 CE. Another thing we need to keep in mind if we are working with earlier versions is that we need to work on upgrading the code as well as the customization upgrade. This is because our Dynamics CRM may be using methods and service references that are deprecated already.

While planning for the upgrade or suggesting an upgrade for any customer, the first question that comes to mind is: Why should we upgrade? The most common reason to upgrade any software system is to gain benefits from the features released in the new version. In Chapter 1, Introduction to Dynamics 365 CE, we discussed the top 10 features of Dynamics 365 CE, which should give us at least one good reason to upgrade our existing Dynamics CRM to Dynamics 365 CE.

Another question that we face is: How do we upgrade to Dynamics 365 CE? If we are using online versions, then we don't need to bother about this question as online deployment is upgraded by Microsoft, but we need to take care of upgrading our customization and code. Also, keep in mind that Microsoft now releases a platform update twice a year (April and October), and normally, about 9 weeks prior to the update, they release update notes. After about 1 week, customers have the ability to apply early access to this update with a sandbox environment, to test all customization and coding. But, if we are working with an on-premises environment, then we need to plan our upgrade depending on different points. For example:

• Does the existing server support Dynamics 365 CE configuration?
• Do we have new servers in case we want to set up Dynamics 365 CE on new servers?
• Do we have the required IT team to take care of setting up the environment for Dynamics 365 CE?
• How much downtime is supported in case we want to use our existing infrastructure for Dynamics 365 CE?

All of the preceding points decide how we are going to upgrade and what our upgrade activities will be. We can list down the upgrade process using the following diagram, where we have common steps that we perform for any type of upgrade:

Before the upgrade, our first step is to prepare an assessment report that includes all the details of our current Dynamics CRM environment. After that, we work on the deployment plan that we are going to select based on our requirements, and it is recommended to do a trial upgrade to understand the complications involved in the upgrade. Finally, we perform testing on the upgraded environment, which involves functional testing as well as user acceptance testing (UAT), before it is released to the end users.

Now that we have introduced the high-level details of a Dynamics CRM upgrade, let's discuss those high-level activities in more detail.