Senior Developers Team Productivity X4 (from MS Research Paper)

There is a very interesting MS Research paper about test driven development (TDD). It is one of the only real study about it that I know of. The paper conclusions from experiments over 4 TDD teams vs 4 traditional teams is:

"TDD seems to be applicable in various domains and can significantly reduce the defect density of developed software without significant productivity reduction of the development team"

Their data gives also other interesting results:

• An experienced team (5 people over 10 years + 2 people under 5 years) : 155KLOC C# code (+60 test).
  

• A junior team (3 people under 10 years + 6 people under 5 years): 41 KLOC Java code (+28 test).
  

If you do the ratio of KLOC/man month, you have the following graph:

I know this is very far from scientific evidence and more like astrology, but still, the most conservative ratio for senior/junior is 4.23!

Senior Developers Team Productivity X4 (from MS Research Paper)

There is a very interesting MS Research paper about test driven development (TDD). It is one of the only real study about it that I know of. The paper conclusions from experiments over 4 TDD teams vs 4 traditional teams is:

"TDD seems to be applicable in various domains and can significantly reduce the defect density of developed software without significant productivity reduction of the development team"

Their data gives also other interesting results:

• An experienced team (5 people over 10 years + 2 people under 5 years) : 155KLOC C# code (+60 test).
  

• A junior team (3 people under 10 years + 6 people under 5 years): 41 KLOC Java code (+28 test).
  

If you do the ratio of KLOC/man month, you have the following graph:

I know this is very far from scientific evidence and more like astrology, but still, the most conservative ratio for senior/junior is 4.23!