Foreign philology

Tursyngazy Akerke

Student in KazUIRand RL named after Abilaykhan 3course

Basic behavioral models for software product lines.

Abstract

In Beohar et al. (2016) , we established an expressiveness hierarchy and studied the notions of refinement and testing for three fundamental behavioral models for software product lines. These models were featured transition systems, product line labeled transition systems, and modal transition systems. It turns out that our definition of product line labeled transition systems is more restrictive than the one introduced by Gruler, Leucker, and Scheidemann. Adopting the original and more liberal notion changes the expressiveness results, as we demonstrate in this paper. Namely, we show that the original notion of product line labeled transition systems and featured transition systems are equally expressive. As an additional result, we show that there are featured transition systems for which the size of the corresponding product line labeled transition system, resulting from any sound encoding, is exponentially larger than the size of the original model. Furthermore, we show that each product line labeled transition system can be encoded into a featured transition system, such that the size of featured transition system is linear in terms of the size of the corresponding model. To summarize, featured transition systems are equally expressive as, but exponentially more succinct than, product line labeled transition systems.

Keywords

Software product lines

Behavioral model

Featured transition systems

Calculus of communicating systems

Product line labeled transition systems

1. Introduction

Software Product Line (SPL) engineering is a software development technique enabling mass production and customization. Using this technique, a family of software systems is efficiently developed based on a common core and by benefiting from systematic reuse of artifacts among products.

There are several quality assurance techniques such as model-based testing and model checking that require a model describing the behavior of the system. Hence, several behavioral models have been proposed that can be used for compactly and efficiently representing the behavior of the products in an SPL; examples of such models are Featured Transition Systems (FTSs) , Product Line Calculus of Communicating Systems (PL-CCSs) , and Modal Transition Systems (MTSs) and different extensions of MTSs . These formalisms are comparable in terms of the types of behavior that they can capture and also in terms of their underlying formal model, i.e., Labeled Transition Systems (LTSs).

FTSs are introduced as an extension of LTSs where the transitions are additionally labeled with feature expressions. Each feature expression is a propositional formula in which the variables represent the features of a product family. Feature expressions indicate the presence/absence of a transition in the model of each product (for more details see Section ). Using FTSs, the behavior of all products is represented in a whole model and different types of analysis can be performed for all products at once using this model.

2. Preliminaries

In this section, we provide the definition of constructs and concepts that are used throughout the paper.

2.1. Feature diagram

In SPL engineering, the commonalities and variabilities among products are described using features. A feature is defined as “a prominent or distinctive user-visible aspect, quality, or characteristic of a software system” . Each product in an SPL is defined by a subset of features selected from the whole set of features of the SPL. There are different relations between the features in an SPL. Feature models are a common means to compactly represent the set of products of an SPL in terms of its features.

A feature model is a hierarchical structure consisting of nodes and edges between them. Each node in a feature model represents a feature in the SPL. The structure of a feature model is tree like. Each node can have a set of child nodes. The features in an SPL can be optional, or mandatory. The mandatory features are present in all products of the SPL, while the optional features may be present in a subset of the products. A group of sibling features (nodes) can have the alternative relation, which means only one of the features in the group can be included in a product in case that the parent feature is selected. Also, a group of sibling features can have the orrelation, which means one or more features in the group can be included in a product if the parent feature is selected. There are cross tree relations such as requires (resp. excludes), where the inclusion of a feature results in inclusion (resp. exclusion) of other features. Each feature model can be represented by a propositional logic formula in which propositional variables represent the features in the SPL .

Example 1

An example of a feature model is depicted in . The feature model corresponds to a vending machine product line (the vending machine in this example is a simplified version of the one given in ).

Адрес публикации: https://www.prodlenka.org/metodicheskie-razrabotki/325066-foreign-philology