Database Reference
In-Depth Information
1.1
Strategies for migrating to SAP HANA
There are many ways to move an existing SAP BW system on a traditional database to SAP
BW on HANA, but there are really only two major strategies which most companies con-
sider:
New implementation (greenfield)
Database migration
Within each strategy, there are different approaches and tactics which can be employed.
Let's dive a little deeper into the benefits, approaches, and tactics of both strategies.
1.1.1
New implementation (greenfield) strategy
In a new implementation, or
greenfield
strategy, a conscious decision has been made to in-
stall an entirely new SAP BW on HANA environment. Content (i.e., data models, applica-
tions, and reports) from the original SAP BW system will be redeveloped in the SAP BW
on HANA system. This greenfield system will run in parallel with the existing BW environ-
ment for the duration of time it takes to redesign the entire enterprise data warehouse (EDW)
to fully leverage the benefits of the SAP HANA platform.
When the new system is ready, historical data can be migrated from the old environment
to the greenfield system. As reporting capabilities are rolled out, one or more production
cutovers can be scheduled to transition the business to the new system, thus enabling a flex-
ible deployment approach.
The biggest deterrent to the greenfield approach is the cost of implementation and the lost
investment in the original system. Depending on the size and complexity of the original SAP
BW system, a greenfield approach could take multiple years to completely redesign and re-
build, thus requiring a dual landscape (twice the infrastructure and twice the support) during
that time. For systems with severe design issues or minimal content, the effort of rebuilding
from scratch may be well worth it considering the benefits of this strategy.
The biggest benefit of the greenfield strategy is that it provides an opportunity to completely
discard and/or replace old, outdated, and overly complex data models. In many cases, data
models and data flows designed for reporting efficiency in traditional SAP BW implementa-
