Cloud Migration Strategy Sankey Diagram: Apps to Status
Map an application portfolio from business area to migration strategy (rehost, replatform, refactor, repurchase, retire, retain) to status. Replace the sample counts with your inventory.
A cloud migration Sankey shows a portfolio in one picture: which applications each business area owns, what you decided to do with each, and how far along it is. It makes the share that will never move visible.
The example has 100 applications in four business areas. They go to six strategies: rehost, replatform, refactor, repurchase, retire and retain. The last column shows the status: 43 live in the cloud, 21 in progress, 20 not started, 9 switched off and 7 staying on-premises.
A migration plan is often reported as a percentage complete. The Sankey shows what the percentage hides, such as that 22 applications will not move at all and that the largest block of not-started work is retirement (6 applications). Use /guides/how-to-find-bottlenecks-in-a-software-release-process for the delivery side, and /sankey/cloud-cost-allocation for what the target environment will cost.
How to read this diagram
- 43 of 100 applications (43%) are live in the cloud, 21 are in progress and 20 have not started.
- Rehost is the largest strategy at 35 applications (35%); refactor is only 10.
- 22 applications (22%) will not move: 15 are retired and 7 are retained on-premises.
- Refactoring has the weakest progress: 2 of 10 are live and 4 have not started.
The data behind it
Invented figures for illustration. Not data about any real company, team or system.
| From | To | Amount (applications) |
|---|---|---|
| Finance | Rehost | 10 |
| Finance | Replatform | 8 |
| Finance | Refactor | 3 |
| Finance | Repurchase | 2 |
| Finance | Retire | 3 |
| Finance | Retain | 4 |
| Sales | Rehost | 8 |
| Sales | Replatform | 5 |
| Sales | Refactor | 2 |
| Sales | Repurchase | 5 |
| Sales | Retire | 4 |
| Sales | Retain | 1 |
| Operations | Rehost | 14 |
| Operations | Replatform | 9 |
| Operations | Refactor | 4 |
| Operations | Retire | 6 |
| Operations | Retain | 2 |
| HR | Rehost | 3 |
| HR | Replatform | 3 |
| HR | Refactor | 1 |
| HR | Repurchase | 1 |
| HR | Retire | 2 |
| Rehost | Live in the cloud | 25 |
| Rehost | In progress | 7 |
| Rehost | Not started | 3 |
| Replatform | Live in the cloud | 12 |
| Replatform | In progress | 8 |
| Replatform | Not started | 5 |
| Refactor | Live in the cloud | 2 |
| Refactor | In progress | 4 |
| Refactor | Not started | 4 |
| Repurchase | Live in the cloud | 4 |
| Repurchase | In progress | 2 |
| Repurchase | Not started | 2 |
| Retire | Switched off | 9 |
| Retire | Not started | 6 |
| Retain | Staying on-premises | 7 |
The same data as CSV
source,target,value
Finance,Rehost,10
Finance,Replatform,8
Finance,Refactor,3
Finance,Repurchase,2
Finance,Retire,3
Finance,Retain,4
Sales,Rehost,8
Sales,Replatform,5
Sales,Refactor,2
Sales,Repurchase,5
Sales,Retire,4
Sales,Retain,1
Operations,Rehost,14
Operations,Replatform,9
Operations,Refactor,4
Operations,Retire,6
Operations,Retain,2
HR,Rehost,3
HR,Replatform,3
HR,Refactor,1
HR,Repurchase,1
HR,Retire,2
Rehost,Live in the cloud,25
Rehost,In progress,7
Rehost,Not started,3
Replatform,Live in the cloud,12
Replatform,In progress,8
Replatform,Not started,5
Refactor,Live in the cloud,2
Refactor,In progress,4
Refactor,Not started,4
Repurchase,Live in the cloud,4
Repurchase,In progress,2
Repurchase,Not started,2
Retire,Switched off,9
Retire,Not started,6
Retain,Staying on-premises,7How it works
Export the application inventory
List each application with its owning business area, your migration decision and its current status.
Use one strategy per application
Pick the main strategy for each and count it once. Split an application in the inventory if two parts differ.
Count the flows
Count applications from area to strategy and from strategy to status.
Check the balance
Each strategy must leave as many applications as entered. Retain and the final statuses end there.
Frequently asked questions
Do I need to use the six strategies?
No. The 6 Rs are a common vocabulary, but you can use your own labels. Keep the number small so the middle column stays readable.
Can I weight applications by cost or size?
Yes: make the unit euros of annual run cost or servers instead of applications, and say so. A count and a cost tell different stories.
Edit this cloud migration Sankey
Open the example as your own chart and enter your application counts.