These migration strategies are adopted from Gartner research. Gartner also calls out a fifth strategy called replace with SaaS.
The following research paper is discussed in this section:
Devise an Effective Cloud Computing Strategy by Answering Five Key Questions, Gartner, David W Cearley, November 2015, refreshed June 23, 2017.
When migrating to the cloud, we don't have to see the cloud as a destination, but rather as a journey. As cheesy as it sounds, it is like that. Every customer’s path to the cloud will be different; some paths will be easy and others will be painfully hard. It will all depend on what led the customer to take the decision to move and how they are deciding to move their infrastructure. Some customers might decide not only to move their infrastructure to an IaaS model but also take advantage of the move and modernize some of the workloads into a PaaS or even a serverless model. Each path will require a different level of preparation, regardless of which one they choose. A typical transition can look as follows:
Each step will require a higher degree of changes to be implemented on the applications or infrastructure to migrate.
We can see the aforementioned steps as part of a greater journey that begins with the assessment of the assets to migrate.
Let's explore each step of the migration in more detail.