  Recent research has proposed different approaches on the automated
identification of candidate microservices on monolith systems, which vary on
the monolith representation, similarity criteria, and quality metrics used. On
the other hand, they are generally limited in the number of codebases and
decompositions evaluated, and few comparisons between approaches exist.
Considering the emerging trend in software engineering in techniques based on
the analysis of codebases' evolution, we compare a representation based on the
monolith code structure, in particular the sequences of accesses to domain
entities, with representations based on the monolith development history (file
changes and changes authorship). From the analysis on a total of 468k
decompositions of 28 codebases, using five quality metrics that evaluate
modularity, minimization of the number of transactions per functionality, and
reduction of teams and communication, we conclude that the best decompositions
on each metric were made by combining data from the sequences of accesses and
the development history representations. We also found that the changes
authorship representation of codebases with many authors achieves comparable or
better results than the sequence of accesses representation of codebases with
few authors with respect to minimization of the number of transactions per
functionality and the reduction of teams.
