This paper focuses on the version models underlying both commercial systems and research prototypes. It provides an overview and classification of different versioning paradigms. Furthermore, it defines and relates fundamental concepts such as revisions, variants, configurations, and changes. In particular, we focus on intensional versioning, i.e., construction of versions based on configuration rules. Finally,we provide an overview of systems whichhave had significant impact on the development of the SCM discipline, and classify them according to a detailed taxonomy

We apply mathematical concept analysis to the problem of reengineering configurations. Concept analysis will reconstruct a taxonomy of concepts from a relation between objects and attributes. We use concept analysis to infer configuration structures from existing source code. Our tool NORA/RECS will accept source code, where configuration-specific code pieces are controlled by the preprocessor. The algorithm will compute a so-called concept lattice, which —when visually displayed — offers remarkable insight into the structure and properties of possible configurations. The lattice not only displays tine-grained dependencies between configurations, but also visualizes the overall quality of configuration structures according to software engineering principles. In a second step, interferences between configurations can be analyzed in order to restructure or simplify configurations. Interferences showing up in the lattice indicate high coupling and low cohesion between configuration concepts. Source files can then be simplified according to the lattice structure. Finally, we show how governing expressions can be simplified by utilizing an isomorphism theorem of mathematical concept analysis.

A rich variety of version models for software configuration management (SCM) has been proposed over the years, and understanding of the basic concepts and their interrelations has been growing accordingly.

Version management is a key function of software configuration management (SCM). A big variety of version models has been realized in both commercial systems and research prototypes. These version models differ with respect to the objects put under version control (files, directories, entitles, objects), the organization of versions (version graphs rs. multi-dimensional version spaces), the granularity of versioning (whole software products rs. individual components), emphasis on states rs. emphasis on changes (staters. change-based versioning), rules for version selection, etc. We present UVM, a Uniform Version Model - and its support architecture - for SCM. Unlike other unification approaches such as e.g. UML for object-oriented modeling, we do not assemble all the concepts having been introduced in previous systems. Instead, we define a base model that is built on a small number of concepts. Specific version models may be expressed in terms of this base model. Our approach

Despite recent advances in software configuration management (SCM), constructing consistent configurations of large and complex versioned software products still remains a challenge. We provide an overview of existing approaches which address this problem. These approaches are compared by means of a taxonomy which is based on an analogy to deductive databases: construction of a configuration corresponds to evaluation of a query against a versioned database with stored version selection rules.

Feature trees are the formal basis for algorithms manipulating record like structures in constraint programming, computational linguistics and in concrete applications like software configuration management. Feature trees model records, and constraints over feature trees yield extensible and modular record descriptions. We introduce the constraint system FT of ordering constraints interpreted over feature trees. Under the view that feature trees represent symbolic information, the relation corresponds to the information ordering ("carries less information than"). We present two algorithms in cubic time, one for the satisfiability problem and one for the entailment problem of FT . We show that FT has the independence property. We are thus able to handle negative conjuncts via entailment and obtain a cubic algorithm that decides the satisfiability of conjunctions of positive and negated ordering constraints over feature trees. Furthermore, we reduce the satisfiability problem of Dorre's weak subsumption constraints to the satisfiability problem of FT and improve the complexity bound for solving weak subsumption constraints from O(n^5) to O(n³).

In the paper, the question of effective automated version selection is tackled. It is an important part of a method for building a software configuration. The paper concentrates on the method for version selection which allows specifying requirements which refer to properties of versions. It is controlled by knowledge in form of heuristic functions serving as necessary condition and suitability condition for selection. We present the method and describe its application in selecting software components. Keywords: software configuration management, version control, selection controlled by heuristics 1 Introduction The problem of version selection is a topic of much interest in the recent research within the area of software configuration management. Solving it is important for achieving quality of the configuration being built, but it also influences efficiency of the process of building a software system configuration. Requirements for version selection can have various forms: ffl a...

Implementing software configuration management (SCM) in an organization raises various integration problems. We present the Incremental Configuration Environment (ICE), a novel SCM system providing smooth integration with both the software process and the development environment. ICE is based on the version set model, where versions, components, and aggregates are grouped into sets according to their features, using feature logic as a formal base to denote sets and operations and to deduce consistency. Version sets generalize well-known SCM concepts such as components, repositories, workspaces, aggregates, or configurations and allow for flexibility in combining these concepts. For integration in software development environments, ICE provides a featured file system (FFS), where version sets are represented as files and directories. In the FFS, arbitrary programs can incrementally access and explore version sets. Using the well-known C preprocessor (CPP) representation, users can vi...

Integration of configuration management (CM) tools into software development environments raises the need for CM models to interoperate through a unified CM model. We present the version set model, where versions, components, and aggregates are grouped into sets according to their features, using feature logic as a formal base to denote sets and operations and deduce consistency. Version sets generalize well-known CM concepts such as components, repositories, workspaces, aggregates, or configurations. Arbitrary revision/variant combinations of components and aggregates are modeled in a uniform and orthogonal way. We show how the concepts of four central configuration management models---the checkin/ checkout model, the change set model, the composition model, and the long transaction model--- are encompassed and extended by the version set model, making it a unified basis for modeling, realizing and integrating configuration management tasks. Finally, some conditions for efficient real...

ABSTRACT- In the continually changing world of computing, the Web is an example of an environment where information evolves very rapidly. In addition to Web information that changes very much and very frequently, Webmasters are faced with hard work when many people are involved in the parallel development of a set of related Web pages. In the face of such problems, a software tool, VersionWeb, was developed. The idea behind this tool is to make Web page version control available during browsing to users. The main goal of VersionWeb is to provide the Webmasters with an easy way of controlling Web page versions, through the Web itself.