Analyzing software data bindings in large-scale systems

One central feature of the structure of a software system is the coupling among its components (e.g., subsystems. modules) and the cohesion within them. The purpose of this study is to quantify ratios of coupling and cohesion and use them in the generation of hierarchical system descriptions. The ability of the hierarchical descriptions to localize errors by identifying error-prone system structure is evaluated using actual error data. Measures of data interaction, called data bindings, are used as the basis for calculating software coupling and cohesion. A 135,000 source line system from a production environment has been selected for empirical analysis. Software error data was collected from high-level system design through system test and from some field operation of the system. A set of five tools is applied to calculate the data bindings automatically, and cluster analysis is used to determine a hierarchical description of each of the system's 77 subsystems. An analysis of variance model is used to characterize subsystems and individual routines that had either many/few errors or high/low error correction effort

Capability Coordination in Modular Organization: Voluntary FS/OSS Production and the Case of Debian GNU/Linux

The paper analyzes voluntary Free Software/Open Source Software (FS/OSS) organization of work. The empirical setting considered is the Debian GNU/Linux operating system. The paper finds that the production process is hierarchical notwithstanding the modular (nearly decomposable) architecture of software and of voluntary FS/OSS organization. But voluntary FS/OSS project organization is not hierarchical for the same reasons suggested by the most familiar theories of economic organization: hierarchy is justified for coordination of continuous change, rather than for the direction of static production. Hierarchy is ultimately the overhead attached to the benefits engendered by modular organization.Modularity, hierarchy, capabilities, coordination costs, software.

Heuristic Solutions for Loading in Flexible Manufacturing Systems

Production planning in flexible manufacturing system deals with the efficient organization of the production resources in order to meet a given production schedule. It is a complex problem and typically leads to several hierarchical subproblems that need to be solved sequentially or simultaneously. Loading is one of the planning subproblems that has to addressed. It involves assigning the necessary operations and tools among the various machines in some optimal fashion to achieve the production of all selected part types. In this paper, we first formulate the loading problem as a 0-1 mixed integer program and then propose heuristic procedures based on Lagrangian relaxation and tabu search to solve the problem. Computational results are presented for all the algorithms and finally, conclusions drawn based on the results are discussed

Holographic Reduced Representations for Oscillator Recall: A Model of Phonological Production

This paper describes a new computational model of phonological production, Holographic Reduced Representations for Oscillator Recall, or HORROR. HORROR's architecture accounts for phonological speech error patterns by combining the hierarchical oscillating context signal of the OSCAR serial-order model~\cite{VousdenEtAl:2000,BrownEtAl:2000} with a holographic associative memory~\cite{Plate:1995}. The resulting model is novel in a number of ways. Most importantly, all of the noise needed to generate errors is intrinsic to the system, instead of being generated by an external process. The model features fully-distributed hierarchical phoneme representations and a single distributed associative memory. Using fewer parameters and a more parsimonious design than OSCAR, HORROR accounts for error type proportions, the syllable-position constraint, and other constraints seen in the human speech error data

Deriving safety cases for hierarchical structure in model-based development

Model-based development and automated code generation are increasingly used for actual production code, in particular in mathematical and engineering domains. However, since code generators are typically not qualified, there is no guarantee that their output satisfies the system requirements, or is even safe. Here we present an approach to systematically derive safety cases that argue along the hierarchical structure in model-based development. The safety cases are constructed mechanically using a formal analysis, based on automated theorem proving, of the automatically generated code. The analysis recovers the model structure and component hierarchy from the code, providing independent assurance of both code and model. It identifies how the given system safety requirements are broken down into component requirements, and where they are ultimately established, thus establishing a hierarchy of requirements that is aligned with the hierarchical model structure. The derived safety cases reflect the results of the analysis, and provide a high-level argument that traces the requirements on the model via the inferred model structure to the code. We illustrate our approach on flight code generated from hierarchical Simulink models by Real-Time Worksho

Development of the Integrated Model of the Automotive Product Quality Assessment

Issues on building an integrated model of the automotive product quality assessment are studied herein basing on widely applicable methods and models of the quality assessment. A conceptual model of the automotive product quality system meeting customer requirements has been developed. Typical characteristics of modern industrial production are an increase in the production dynamism that determines the product properties; a continuous increase in the volume of information required for decision-making, an increased role of knowledge and high technologies implementing absolutely new scientific and technical ideas. To solve the problem of increasing the automotive product quality, a conceptual structural and hierarchical model is offered to ensure its quality as a closed system with feedback between the regulatory, manufacturing, and information modules, responsible for formation of the product quality at all stages of its life cycle. The three module model of the system of the industrial product quality assurance is considered to be universal and to give the opportunity to explore processes of any complexity while solving theoretical and practical problems of the quality assessment and prediction for products for various purposes, including automotive