Title
What Does It Take to Develop a Million Lines of Open Source Code?
Abstract
This article presents a preliminary and exploratory study of the relationship between size, on the one hand, and effort, duration and team size, on the other, for 11 Free/Libre/Open Source Software (FLOSS) projects with current size ranging between between 0.6 and 5.3 million lines of code (MLOC). Effort was operationalised based on the number of active committers per month. The extracted data did not fit well an early version of the closed-source cost estimation model COCOMO for proprietary software, overall suggesting that, at least to some extent, FLOSS communities are more productive than closed-source teams. This also motivated the need for FLOSS-specific effort models. As a first approximation, we evaluated 16 linear regression models involving different pairs of attributes. One of our experiments was to calculate the net size, that is, to remove any suspiciously large outliers or jumps in the growth trends. The best model we found involved effort against net size, accounting for 79 percent of the variance. This model was based on data excluding a possible outlier (Eclipse), the largest project in our sample. This suggests that different effort models may be needed for certain categories of FLOSS projects. Incidentally, for each of the I I individual FLOSS projects we were able to model the net size trends with very high accuracy (R-2 >= 0.98). Of the 11 projects, 3 have grown superlinearly, 5 linearly and 3 sublinearly, suggesting that in the majority of the cases accumulated complexity is either well controlled or don't constitute a growth constraining factor.
Year
DOI
Venue
2009
10.1007/978-3-642-02032-2_16
International Federation for Information Processing
Keywords
Field
DocType
Baselines,complexity,COCOMO,cost,economics,effort estimation,effort operationalisation,empirical studies,large software,free software,metrics,open source,productivity,software evolution
Source code,Computer science,Outlier,Cost estimate,Software,COCOMO,Statistics,Software evolution,Linear regression,Source lines of code
Conference
Volume
ISSN
Citations 
299
1571-5736
9
PageRank 
References 
Authors
0.59
16
3
Name
Order
Citations
PageRank
Juan Fernández-Ramil1292.44
Daniel Izquierdo-Cortazar214312.86
Tom Mens33018181.32