Be the best you can be and diversify your skill set.

- To be the best you can be as a developer, you need to be able to know how to test.

- To be the best you can be as a tester, you need to be able to know how to develop.

- To be the best you can be as a business analyst/owner, you need to be able to know how to design an application.

- To be the best you can be as a system designer/architect, you need to be able to know how to perform business analysis.

Agile brings all these aspects to the team as a unit and takes advantage of each individual's skill set; not only one skill. This will maximize each individuals ability in a project, at the same time promoting the learning of other skills to maximize their own input within the team

- Last but not least, to be the best Software System Manager, you should know all the above.

In summary, be the best you can be and diversify your skills set!!