5. … leading to lower producKvity
Late error detecKon
Developers discover the problem only when compiling and
execu?ng the problema?c product
Difficult navigaKon
Developers not aware of feature dependencies
Even worse when using VSoC: features are hidden!
5
12. Study secngs
43 Preprocessor‐based SoMware Product lines
Java and C
Different sizes and domains
Script tool for compu?ng two metrics:
MDi: number of methods with preprocessor direc?ves
MDe: number of methods with feature dependencies
12
15. Methods selecKon
Randomly methods selec?on
Only methods that contain the feature dependencies
we focus on this work
Which methods should we select?
Many fragments: favoring emergent interfaces
Few fragments: no differences
15
22. Our data reveal that…
Methods with direc?ves that also contain the
feature dependencies we studied:
Max: 88% (mobile‐rss)
Min: 12% (lampiro)
So, the feature dependencies we considered may
be common in the 43 SPLs we analyzed
Only 6 SPLs have MDe/MDi < 50%
22
26. When increasing the number of
fragments…
… the percentage of methods where Emergent
Interfaces achieve effort reduc?on also increases…
100%
EsKmaKon of Effort reducKon
95%
90%
85%
Replica?on 1
80% Replica?on 2
Replica?on 3
75%
70%
65%
> 2 > 3 > 4 > 5 > 6
Number of Fragments 26
27. Threats to validity
Metrics and effort es?ma?on
Time beher measures effort…
… but the metrics are s?ll useful
Overhead to compute emergent interfaces
Dependencies
Interprocedural, chain of assignments… (not computed)
So, the numbers we presented might be even higher…
27
28. Concluding remarks
How
oMen the feature dependencies we analyzed
occur in prac?ce?
Max: 88%; Min: 12%; Majority > 50%
Emergent interfaces can achieve effort reduc?on
For the majority of the studied methods (65%): same
effort of VSoC
Nega?ve impact of VSoC is not so common
More
significant effort reduc?ons: methods with
many fragments (Group 1)
28