A lingualization strategy for knowledge sharing in large-scale DevOps

DevOps has become a generally accepted practice for software projects in the last decade and approaches certain shortcomings of the agile software development and the steadily gaining popularity of cloud infrastructure. While it shifts more and more responsibilities towards software engineering teams, the prevailing opinion is to keep DevOps teams small to reduce the complexity of inter-team communication. In circumstances where products outgrow the performance capability of a single team, microservice architecture enables multiple DevOps teams to contribute to the same application and meet the increased requirements. Since DevOps teams operate typically self-sufficiently and more or less independently inside an organization, such large-scale DevOps environments are prone to knowledge-sharing barriers. Textual Domain-Specific Languages (DSLs) are one of the cornerstones of DevOps and enable key features like automation and infrastructure provisioning. Nonetheless, most commonly accepted DSLs in the context of DevOps are cumbersome and have a steep learning curve. Thus, they fall short of their potential to truly enable cross-functional collaboration and knowledge sharing, not only between development and operation, but to the whole organization. DevOps teams require tools and DSLs, that treat knowledge sharing and reuse as a first-class citizen, in order to operate sufficiently on a large scale. However, developing DSLs is still presumed as an expensive task which can easily offset the resulting benefits. This dissertation presents a lingualization strategy for addressing the challenge of knowledge sharing in large-scale DevOps. The basic idea is to provide custom-tailored Domain-Specific Modeling Languages (DSMLs) that target single phases of the DevOps lifecycle and ease the DevOps adoption for newly formed teams. The paradigm of Language-Driven Engineering (LDE) bridges the semantic gap between stakeholders by custom-tailored DSMLs and thus is a natural fit for knowledge sharing. Key to a successful practice of LDE is as a new class of stakeholders. In the context of large-scale DevOps, language development can be realized by so-called Meta DevOps teams. Those teams, which themselves practice DevOps internally, manage a centralized repository of small DSMLs and offer them as a service. DevOps teams act as the customers of the Meta DevOps teams and can request new features or complete new DSMLs and provide feedback to already existing DSMLs. The presented Rig modeling environment serves as an exemplary DSML that targets the purpose of Continuous Integration and Deployment (CI/CD), one of the most important building blocks of DevOps. Rig comes with an associated code generator to fully-generate CI/CD workflows from graphical models. Those graphical models provide an executable documentation and assist knowledge-sharing between stakeholders. The fundamental modeling concepts of the lingualization strategy are evaluated against previously published requirements by Bordeleau et al. on a DevOps modeling framework in an industrial context. In addition to that, Rig is evaluated based on results of a workshop during the 6th International School on Tool-Based Rigorous Engineering of Software Systems. Both evaluations yield encouraging results and demonstrate the potential of the lingualization strategy to break down knowledge-sharing barriers in large-scale DevOps environments

Model Variations and Automated Refinement of Domain-Specific Modeling Languages for Robot-Motion Control

This paper presents an approach to handling frequent variations of modeling languages and models. The approach is based on Domain-Specific Modeling and linking of modeling tools with adaptive Run-Time Systems. The applicability of our solution is illustrated on an example of domain-specific languages for robot control. Special attention was given to the following problems: 1) model-level debugging; 2) performing fast transformation of models to native code for various hardware platforms and operating systems; and 3) specification of views and view-based generation of applications for validation of meta-models, models, and generated code. The feedback for automated refinement of models and meta-models is provided by a custom adaptive Run-Time System. For the purpose of synchronizing models, meta-models, and the target Run-Time System, we introduce action reports, which allow model-level debugging. In order to simplify handling of frequent model variations, we have introduced the linguistic concept of a modifier

A Systematic Approach to Constructing Incremental Topology Control Algorithms Using Graph Transformation

Communication networks form the backbone of our society. Topology control algorithms optimize the topology of such communication networks. Due to the importance of communication networks, a topology control algorithm should guarantee certain required consistency properties (e.g., connectivity of the topology), while achieving desired optimization properties (e.g., a bounded number of neighbors). Real-world topologies are dynamic (e.g., because nodes join, leave, or move within the network), which requires topology control algorithms to operate in an incremental way, i.e., based on the recently introduced modifications of a topology. Visual programming and specification languages are a proven means for specifying the structure as well as consistency and optimization properties of topologies. In this paper, we present a novel methodology, based on a visual graph transformation and graph constraint language, for developing incremental topology control algorithms that are guaranteed to fulfill a set of specified consistency and optimization constraints. More specifically, we model the possible modifications of a topology control algorithm and the environment using graph transformation rules, and we describe consistency and optimization properties using graph constraints. On this basis, we apply and extend a well-known constructive approach to derive refined graph transformation rules that preserve these graph constraints. We apply our methodology to re-engineer an established topology control algorithm, kTC, and evaluate it in a network simulation study to show the practical applicability of our approachComment: This document corresponds to the accepted manuscript of the referenced journal articl

Mallipohjainen järjestelmäintegraatio tuotannonohjausjärjestelmille

Application integration becomes more complex as software becomes more advanced. This thesis investigates the applicability of model-driven application integration methods to the software integration of manufacturing execution systems (MES). The goal was to create a code generator that uses models to generate a working program that transfers data from a MES to another information system. The focus of the implementation was on generality. First, past research of MES was reviewed, the means to integrate it with other information systems were investigated, and the international standard ISA-95 and B2MML as well as model-driven engineering (MDE) were revised. Next, requirements were defined for the system. The requirements were divided into user and developer requirements. A suitable design for a code generator was introduced and, after that, implemented and experimented. The experiment was conducted by reading production data from the database of MES-like Delfoi Planner and then transforming that data to B2MML-styled XML-schema. The experiment verified that the code generator functioned as intended. However, compared to a manually created program, the generated code was longer and less efficient. It should also be considered that adopting MDE methods takes time. Therefore, for MDE to be better than traditional programming, the code generator has to be used multiple times in order to achieve the benefits and the systems cannot be too time-critical either. Based on the findings, it can be said, that model-driven application integration methods can be used to integrate MESs, but there are restrictions.Järjestelmäintegraatio vaikeutuu ohjelmien monimutkaistuessa. Tässä työssä tutkitaan mallipohjaisten järjestelmäintegraatiometodien soveltuvuutta tuotannonohjausjärjestelmille (MES). Tavoitteena oli muodostaa koodigeneraattori, joka käyttää malleja luodakseen toimivan ohjelman, joka siirtää tietoa MES-järjestelmästä johonkin toiseen tietojärjestelmään. Toteutuksessa keskityttiin yleistettävyyteen. Aluksi työssä käytiin läpi aikaisempaa tutkimusta MES-järjestelmistä ja mahdollisuuksista integroida niitä toisiin informaatiojärjestelmiin. Lisäksi otettiiin selvää kansainvälisestä ISA-95 standardista ja B2MML:sta sekä mallipohjaisesta tekniikasta (MDE). Tämän jälkeen järjestelmälle määriteltiin vaatimukset, jotka jaettiin käyttäjän ja kehittäjän vaatimuksiin. Koodigeneraattorista tehtiin ehdot täyttävä suunnitelma, joka toteutettiin ja jolla suoritettiin kokeita. Koe toteutettiin lukemalla tuotantodataa MES:n kaltaisen Delfoi Plannerin tietokannasta, jonka jälkeen data muutettiin B2MML tyyliä noudattavaan XML-schema muotoon. Kokeet osoittivat, että koodigeneraattori toimi kuten toivottiin. Kuitenkin havaittiin, että verrattuna manuaalisesti toteutettuun ohjelmaan, luotu ohjelma ei ollut yhtä tehokas ja lisäksi se oli pidempi. Huomattiin myös, että MDE-metodien käyttöönotto vie paljon aikaa. Jotta MDE olisi perinteistä ohjelmointia parempi vaihtoehto, sitä pitäisi käyttää useita kertoja ja sillä luotu järjestelmä ei saisi olla liian aikariippuvainen. Havaintojen perusteella voidaan sanoa, että mallipohjaisia järjestelmäintegraatiometodeja voidaan käyttää MES-järjestelmien integrointiin, mutta sille on rajoituksia

On the Quality Properties of Model Transformations: Performance and Correctness

The increasing complexity of software due to continuous technological advances has motivated the use of models in the software development process. Initially, models were mainly used as drafts to help developers understand their programs. Later they were used extensively and a new discipline called Model-Driven Engineering (MDE) was born. In the MDE paradigm, aside from the models themselves, model transformations (MT) are garnering interest as they allow the analysis and manipulation of models. Therefore, the performance, scalability and correctness of model transformations have become critical issues and thus they deserve a thorough study. Existing model transformation engines are principally based on sequential and in-memory execution strategies, and hence their capabilities to transform very large models in parallel and in distributed environments are limited. Current tools and languages are not able to cope with models that are not located in a single machine and, even worse, most of them require the model to be in a single file. Moreover, once a model transformation has been written and executed-either sequentially or in parallel-it is necessary to rely on methods, mechanisms, and tools for checking its correctness. In this dissertation, our contribution is twofold. Firstly, we introduce a novel execution platform that permits the parallel execution of both out-place and in-place model transformations, regardless of whether the models fit into a single machine memory or not. This platform can be used as a target for high-level transformation language compilers, so that existing model transformations do not need to be rewritten in another language but only have to be executed more efficiently. Another advantage is that a developer who is familiar with an existing model transformation language does not need to learn a new one. In addition to performance, the correctness of model transformations is an essential aspect that needs to be addressed if MTs are going to be used in realistic industrial settings. Due to the fact that the most popular model transformation languages are rule-based, i.e., the transformations written in those languages comprise rules that define how the model elements are transformed, the second contribution of this thesis is a static approach for locating faulty rules in model transformations. Current approaches able to fully prove correctness-such as model checking techniques-require an unacceptable amount of time and memory. Our approach cannot fully prove correctness but can be very useful for identifying bugs at an early development stage, quickly and cost effectively

A Catalog of Reusable Design Decisions for Developing UML/MOF-based Domain-specific Modeling Languages

In model-driven development (MDD), domain-specific modeling languages (DSMLs) act as a communication vehicle for aligning the requirements of domain experts with the needs of software engineers. With the rise of the UML as a de facto standard, UML/MOF-based DSMLs are now widely used for MDD. This paper documents design decisions collected from 90 UML/MOF-based DSML projects. These recurring design decisions were gained, on the one hand, by performing a systematic literature review (SLR) on the development of UML/MOF-based DSMLs. Via the SLR, we retrieved 80 related DSML projects for review. On the other hand, we collected decisions from developing ten DSML projects by ourselves. The design decisions are presented in the form of reusable decision records, with each decision record corresponding to a decision point in DSML development processes. Furthermore, we also report on frequently observed (combinations of) decision options as well as on associations between options which may occur within a single decision point or between two decision points. This collection of decision-record documents targets decision makers in DSML development (e.g., DSML engineers, software architects, domain experts).Series: Technical Reports / Institute for Information Systems and New Medi

Model Driven Development and Maintenance of Business Logic for Information Systems

Since information systems become more and more important in today\''s society, business firms, organizations, and individuals rely on these systems to manage their daily business and social activities. The dependency of possibly critical business processes on complex IT systems requires a strategy that supports IT departments in reducing the time needed to implement changed or new domain requirements of functional departments. In this context, software models help to manage system\''s complexity and provide a tool for communication and documentation purposes. Moreover, software engineers tend to use automated software model processing such as code generation to improve development and maintenance processes. Particularly in the context of web-based information systems, a number of model driven approaches were developed. However, we believe that compared to the user interface layer and the persistency layer, there could be a better support of consistent approaches providing a suitable architecture for the consistent model driven development of business logic. To ameliorate this situation, we developed an architectural blueprint consisting of meta models, tools, and a method support for model driven development and maintenance of business logic from analysis until system maintenance. This blueprint, which we call Amabulo infrastructure, consists of five layers and provides concepts and tools to set up and apply concrete infrastructures for model driven development projects. Modeling languages can be applied as needed. In this thesis we focus on business logic layers of J2EE applications. However, concrete code generation rules can be adapted easily for different target platforms. After providing a high-level overview of our Amabulo infrastructure, we describe its layers in detail: The Visual Model Layer is responsible for all visual modeling tasks. For this purpose, we discuss requirements for visual software models for business logic, analyze several visual modeling languages concerning their usefulness, and provide an UML profile for business logic models. The Abstract Model Layer provides an abstract view on the business logic model in the form of a domain specific model, which we call Amabulo model. An Amabulo model is reduced to pure logical information concerning business logic aspects. It focuses on information that is relevant for the code generation. For this purpose, an Amabulo model integrates model elements for process modeling, state modeling, and structural modeling. It is used as a common interface between visual modeling languages and code generators. Visual models of the Visual Model Layer are automatically transformed into an Amabulo model. The Abstract System Layer provides a formal view onto the system in the form of a Coloured Petri Net (CPN). A Coloured Petri Net representation of the modeled business logic is a formal structure and independent of the actual business logic implementation. After an Amabulo model is automatically transformed into a CPN, it can be analyzed and simulated before any line of code is generated. The Code Generation Layer is responsible for code generation. To support the design and implementation of project-specific code generators, we discuss several aspects of code integration issues and provide object-oriented design approaches to tackle the issues. Then, we provide a conceptual mapping of Amabulo model elements into architectural elements of a J2EE infrastructure. This mapping explicitly considers robustness features, which support a later manual integration of generated critical code artifacts and external systems. The Application Layer is the target layer of an Amabulo infrastructure and comprises generated code artifacts. These artifacts are instances of a specific target platform specification, and they can be modified for integration purposes with development tools. Through the contributions in this thesis, we aim to provide an integrated set of solutions to support an efficient model driven development and maintenance process for the business logic of information systems. Therefore, we provide a consistent infrastructure blueprint that considers modeling tasks, model analysis tasks, and code generation tasks. As a result, we see potential for reducing the development and maintenance efforts for changed domain requirements and simultaneously guaranteeing robustness and maintainability even after several changes

A heuristic-based approach to code-smell detection

Encapsulation and data hiding are central tenets of the object oriented paradigm. Deciding what data and behaviour to form into a class and where to draw the line between its public and private details can make the difference between a class that is an understandable, flexible and reusable abstraction and one which is not. This decision is a difficult one and may easily result in poor encapsulation which can then have serious implications for a number of system qualities. It is often hard to identify such encapsulation problems within large software systems until they cause a maintenance problem (which is usually too late) and attempting to perform such analysis manually can also be tedious and error prone. Two of the common encapsulation problems that can arise as a consequence of this decomposition process are data classes and god classes. Typically, these two problems occur together – data classes are lacking in functionality that has typically been sucked into an over-complicated and domineering god class. This paper describes the architecture of a tool which automatically detects data and god classes that has been developed as a plug-in for the Eclipse IDE. The technique has been evaluated in a controlled study on two large open source systems which compare the tool results to similar work by Marinescu, who employs a metrics-based approach to detecting such features. The study provides some valuable insights into the strengths and weaknesses of the two approache

Concrete syntax definition for modeling languages

Model Driven Engineering (MDE) promotes the use of models as primary artefacts of a software development process, as an attempt to handle complexity through abstraction, e.g. to cope with the evolution of execution platforms. MDE follows a stepwise approach, by prescribing to develop abstract models further improved to integrate little by little details relative to the final deployment platforms. Thus, the application of an MDE process results in various models residing at various levels of abstraction. Each one of these models is expressed in a modeling language, in which one may find appropriate concepts for the abstraction level considered. Many advocate to use the right (modeling) language for the right purpose. This means that it is sometimes better approach to use small languages specific to the considered domain and abstraction level, than to use general purpose languages (e.g. UML) when they do not perfectly fit the (modeling) needs. As a matter of fact, an MDE development process, which involves many different domains and abstraction levels, should also involve a large variety of modeling languages. Project managers who want to apply an MDE process need to deal with this language proliferation to such an extent that, in the long run, one may infer that language engineers can become major actors of software development teams. We believe that comprehensive modeling language management facilities may considerably alleviate that MDE drawback. Such facilities may include modeling language definition, extension, adaptation, or composition. To define a (modeling) language, one needs to define its abstract syntax, its semantics, and one or more concrete syntaxes. This thesis focuses on concrete syntax definition for modeling languages, when the abstract syntax is given in the form of a metamodel. We will provide solutions both for textual and graphical concrete syntaxes. Some of our experiences in building textual languages (as MTL, a model transformation language), and graphical languages (as Netsilon, a web-application modeler) has shown that a lot of work was spent in implementing interface using traditional techniques, be it a text processor generated from a compiler compiler specification, or a modeler making use of modern 2D graphical libraries. Indeed, abstract and concrete syntax were implemented in a disconnected way, and it was then necessary to assemble them, which became rapidly clumsy while abstract syntax evolved. We built our solution to concrete syntax definition as companions of the abstract syntax. The definition of concrete syntax we propose here made it possible to build automatic tools able to analyze or synthesize models from/to text, and to create graphical modelers. We will present a metamodel for textual concrete syntax definition to construct constructive reversible grammars. We will also propose a technique for graphical concrete syntax definition following a two-step process: specification and realization. Specification is a restrictive approach in which a metamodel defines a graphical concrete syntax. Both relations with abstract syntax and spatial relationships are expressed by means of constraints. The realization step proposes a way to provide the concrete syntax tree a meaning, by attributing it a graphical appearance, and by expressing possible user interactions. The structure of the document is the following. After introducing in deeper details the problem and the general structure of the solution we propose, we will take a tour of MDE, text and graph grammars. Then, we will present Netsilon as an example of an MDE tool to MDE development, which required both the definition of a graphical and a textual modeling language. The two following sections will present the solutions we propose for textual and graphical concrete syntax definition, respectively. Final remarks and possible improvements, especially regarding reusability in general of MDE meta-artifacts (like metamodels or model transformations), and of concrete syntax in particular, will conclude the document