Abstract: There exist dependencies between software product line features,thus the feature modules in feature-oriented programming (FOP) is closely related in the code or structure level．On the other hand,whether the variable features are bound in the applications has destructive impact on the implementation of the feature dependencies,causing the potential problem of feature composition failures during FOP process．This paper analyzed the problem and concluded three main dependency scenarios,besides,proposed a vertical decomposition method for feature modules to solve the problem．Its key mechanism is to introduce variability into the inner part of feature modules,thus the problem can be avoided by composing the codes according to the specific requirements．Furthermore,the method was applied on a software product line of publishing-house profit evaluation systems to validate its effectiveness．

Key words: Feature-oriented programming,Software product line,Feature module composition,Feature dependency