► We explore the relationship between product designs and organizational designs. ► We compare open source software with software developed by commercial firms. ► We measure modularity by capturing ...the level of coupling between components. ► We find that loosely coupled organizations tend to develop more modular products. ► The differences in modularity are substantial—up to a factor of six in our sample.
A variety of academic studies argue that a relationship exists between the structure of an organization and the design of the products that this organization produces. Specifically, products tend to “mirror” the architectures of the organizations in which they are developed. This dynamic occurs because the organization's governance structures, problem solving routines and communication patterns constrain the space in which it searches for new solutions. Such a relationship is important, given that product architecture has been shown to be an important predictor of product performance, product variety, process flexibility and even the path of industry evolution.
We explore this relationship in the software industry. Our research takes advantage of a natural experiment, in that we observe products that fulfill the same function being developed by very different organizational forms. At one extreme are commercial software firms, in which the organizational participants are tightly-coupled, with respect to their goals, structure and behavior. At the other, are open source software communities, in which the participants are much more loosely-coupled by comparison. The mirroring hypothesis predicts that these different organizational forms will produce products with distinctly different architectures. Specifically, loosely-coupled organizations will develop more modular designs than tightly-coupled organizations. We test this hypothesis, using a sample of matched-pair products.
We find strong evidence to support the mirroring hypothesis. In all of the pairs we examine, the product developed by the loosely-coupled organization is significantly more modular than the product from the tightly-coupled organization. We measure modularity by capturing the level of coupling between a product's components. The magnitude of the differences is substantial—up to a factor of six, in terms of the potential for a design change in one component to propagate to others. Our results have significant managerial implications, in highlighting the impact of organizational design decisions on the technical structure of the artifacts that these organizations subsequently develop.
This paper reports data from a study that seeks to characterize the differences in design structure between complex software products. We use design structure matrices (DSMs) to map dependencies ...between the elements of a design and define metrics that allow us to compare the structures of different designs. We use these metrics to compare the architectures of two software productsthe Linux operating system and the Mozilla Web browserthat were developed via contrasting modes of organization: specifically, open source versus proprietary development. We then track the evolution of Mozilla, paying attention to a purposeful "redesign" effort undertaken with the intention of making the product more "modular." We find significant differences in structure between Linux and the first version of Mozilla, suggesting that Linux had a more modular architecture. Yet we also find that the redesign of Mozilla resulted in an architecture that was significantly more modular than that of its predecessor and, indeed, than that of Linux. Our results, while exploratory, are consistent with a view that different modes of organization are associated with designs that possess different structures. However, they also suggest that purposeful managerial actions can have a significant impact in adapting a designs structure. This latter result is important given recent moves to release proprietary software into the public domain. These moves are likely to fail unless the product possesses an "architecture for participation."
Coal rib response during bench mining: A case study Sears, Morgan M.; Rusnak, John; Van Dyke, Mark ...
International journal of mining science and technology,
January 2018, 2018-Jan, 2018-01-00, 20180101, 2018-01-01, Letnik:
28, Številka:
1
Journal Article
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Odprti dostop
In 2016, room-and-pillar mining provided nearly 40% of underground coal production in the United States. Over the past decade, rib falls have resulted in 12 fatalities, representing 28% of the ground ...fall fatalities in U.S. underground coal mines. Nine of these 12 fatalities (75%) have occurred in room-and-pillar mines. The objective of this research is to study the geomechanics of bench room-and-pillar mining and the associated response of high pillar ribs at overburden depths greater than 300 m. This paper provides a definition of the bench technique, the pillar response due to loading, observational data for a case history, a calibrated numerical model of the observed rib response, and application of this calibrated model to a second site.
•We describe a methodology for characterizing the architecture of complex systems.•Our methodology is based upon directed network graphs.•We define three types of architecture: Core–Periphery, ...Multi-Core, and Hierarchical.•We apply our methodology to a sample of 1286 software releases.•We find that most systems in our sample possess a Core–Periphery structure.
In this paper, we describe an operational methodology for characterizing the architecture of complex technical systems and demonstrate its application to a large sample of software releases. Our methodology is based upon directed network graphs, which allows us to identify all of the direct and indirect linkages between the components in a system. We use this approach to define three fundamental architectural patterns, which we label core–periphery, multi-core, and hierarchical. Applying our methodology to a sample of 1286 software releases from 17 applications, we find that the majority of releases possess a “core–periphery” structure. This architecture is characterized by a single dominant cyclic group of components (the “Core”) that is large relative to the system as a whole as well as to other cyclic groups in the system. We show that the size of the Core varies widely, even for systems that perform the same function. These differences appear to be associated with different models of development – open, distributed organizations develop systems with smaller Cores, while closed, co-located organizations develop systems with larger Cores. Our findings establish some “stylized facts” about the fine-grained structure of large, real-world technical systems, serving as a point of departure for future empirical work.
Recent studies have shown that concepts of effective field theory such as naturalness can be profitably applied to relativistic mean-field models of nuclei. Here the analysis by Friar, Madland, and ...Lynn of naturalness in a relativistic point-coupling model is extended. Fits to experimental nuclear data support naive dimensional analysis as a useful principle and imply a mean-field expansion analogous to that found for mean-field meson models.
In 2016,room-and-pillar mining provided nearly 40％ of underground coal production in the United States.Over the past decade,rib falls have resulted in 12 fatalities,representing 28％ of the ground ...fall fatalities in U.S.underground coal mines.Nine of these 12 fatalities (75％) have occurred in room-and-pillar mines.The objective of this research is to study the geomechanics of bench room-and-pillar mining and the associated response of high pillar ribs at overburden depths greater than 300 m.This paper provides a definition of the bench technique,the pillar response due to loading,observational data for a case history,a calibrated numerical model of the observed rib response,and application of this calibrated model to a second site.
A compelling feature of relativistic mean-field phenomenology has been the reproduction of spin-orbit splittings in finite nuclei after fitting only to equilibrium properties of infinite nuclear ...matter. This successful result occurs when the velocity dependence of the equivalent central potential that leads to saturation arises primarily because of a reduced nucleon effective mass. The spin-orbit interaction is then also specified when one works in a four-component Dirac framework. Here the nature of the spin-orbit force in more general chiral effective field theories of nuclei is examined, with an emphasis on the role of the tensor coupling of the isoscalar vector meson (ω) to the nucleon.
This thesis develops and validates a tool called the Design Structure Analysis System (DSAS) to analyze software architecture. DSAS extracts function call dependencies and uses Design Structure ...Matrix (DSM) techniques to display relationships among design elements and calculate measures of design structure for pre-existing designs. The specialized algorithms in DSAS allow the tool to process very large code bases, as compared to prior work which has adopted DSM techniques. The tool comprises four main modules. The architectural view module maps the design structure as the designer defined it. The bus detection module finds and marks system wide shared portions of functionality. The change cost module displays and measures the potential for a change to propagate through the system. Finally, the dependency clustering module heuristically arranges the software dependencies into an idealized form that has limited interactions among different modules. We validate the tool via three methods: (1) comparing the tool's output to existing literature that analyzes theoretical and practical examples of modularity, (2) analyzing code of familiar systems, and (3) analyzing longitudinal code re-designs where we are aware of the architect's intent. Subsequently, we use the tool to examine the hypothesis that distributed teams may produce more modular code than co-located teams. We find data to support this hypothesis by comparing open source systems (assumed to represent distributed teams) to proxies for closed source systems (assumed to represent co-located teams). We conclude by highlighting the contributions of this work, and pointing to future applications that may prove fruitful.
Recently developed chiral effective field theory models provide excellent descriptions of the bulk characteristics of finite nuclei, but have not been tested with other observables. In this work, ...densities from both relativistic point-coupling models and mean-field meson models are used in the analysis of meson-nucleus scattering at medium energies. Elastic scattering observables for 790 MeV/
c
π
± on
208Pb are calculated in a relativistic impulse approximation, using the Kemmer-Duffin-Petiau formalism to calculate the
π
± nucleus optical potential.
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