  Software architecture has been a key research area in the software
engineering community due to its significant role in creating high quality
software. The trend of developing product lines rather than single products has
made the software product line a viable option in the industry. Software
product line architecture is regarded as one of the crucial components in the
product lines, since all of the resulting products share this common
architecture. The increased popularity of software product lines demands a
process maturity evaluation methodology. Consequently, this paper presents an
architecture process maturity model for software product line engineering to
evaluate the current maturity of the product line architecture development
process in an organization. Assessment questionnaires and a rating methodology
comprise the framework of this model. The objective of the questionnaires is to
collect information about the software product line architecture development
process. Thus, in general this work contributes towards the establishment of a
comprehensive and unified strategy for the process maturity evaluation of
software product line engineering. Furthermore, we conducted two case studies
and reported the assessment results, which show the maturity of the
architecture development process in two organizations
