Uniquifying Architecture Visualization through Variable 3D Model Generation
In this paper, we present a method for "uniquifying" 3D software visualizations via systematic generation of unique 3D landmarks using a mixture of 3D modelling and variability modeling techniques.
Software visualization facilitates the interactive exploration of large-scale code bases, e.g., to rediscover the architecture of a legacy system. Visualizations of software structure suffer from repetitive patterns that complicate distinguishing different subsystems and recognizing previously visited parts of an architecture. We leverage variability-modeling techniques to "uniquify" visualizations of subsystems via custom-tailored 3D models of recognizable landmarks: For each subsystem, we derive a descriptor and translate it to a (random but deterministic) configuration of a feature model of variable 3D geometry to support large numbers of different 3D models while capturing the design language of a particular type of landmark. We devised a hybrid variant derivation mechanism using a slots-and-hooks composition system for 3D geometry as well as adjusting visual characteristics, e.g., material. We demonstrate our method by creating various different trophies as landmarks for the visualization of a software system.
Utilizing Software Architecture Recovery to Explore Large-Scale Software Systems in Virtual Reality
In this paper, we describe a method for visualizing the architecture and design of a large-scale software system in virtual reality, so that one can explore and comprehend its structure visually instead of only reading code. We implemented this method in our prototype Immersive Software Archaeology.
Exploring an unfamiliar large-scale software system is challenging especially when based solely on source code. While software visualizations help in gaining an overview of a system, they generally neglect architecture knowledge in their representations, e.g., by arranging elements along package structures rather than functional components or locking users in a specific abstraction level only slightly above the source code. In this paper, we introduce an automated approach for software architecture recovery and use its results in an immersive 3D virtual reality software visualization to aid accessing and relating architecture knowledge. We further provide a semantic zoom that allows a user to access and relate information both horizontally on the same abstraction level, e.g., by following method calls, and vertically across different abstraction levels, e.g., from a member to its parent class. We evaluate our contribution in a controlled experiment contrasting the usefulness regarding software exploration and comprehension of our concepts with those of the established CityVR visualization and the Eclipse IDE.
Visiting Researcher at Università della Svizzera italiana
I visited the REVEAL research group at Università della Svizzera italiana (USI) from September to December 2022.
Experiences with Constructing and Evolving a Software Product Line with Delta-Oriented Programming
In this paper, we report on insights into developing a software product line using delta-oriented programming. The concrete tool used was DeltaJava.
A Software Product Line (SPL) captures families of closely related software variants. The configuration options of an SPL are represented by features. Typically, SPLs are developed in a featurecentric manner and, thus, require different development methods and technologies from developing software products individually. For developers of single systems, this means a shift in paradigm and technology. Especially with invasive variability realization mechanisms, such as Delta-Oriented Programming (DOP), centering development around configurable features realized via source code transformation is commonly expected to pose an obstacle, but concrete experience reports are lacking. In this paper, we investigate how DOP and cutting-edge SPL development tools are picked up by non-expert developers. To this end, we report on our experiences from a student capstone SPL development project. Our results show that participants find easy access to SPL development concepts and tools. Based on our observations and the participants’ practices, we define guidelines for developers using DOP.
Towards Immersive Software Archaeology: Regaining Legacy Systems’ Design Knowledge via Interactive Exploration in Virtual Reality
In this short paper, we outline our goals for the ISA project and what challenges we want to address:
Many of today’s software systems will become the legacy systems of tomorrow, comprised of outdated technology and inaccurate design documents. Preparing for their eventual re-engineering requires engineers to regain lost design knowledge and discover re-engineering opportunities. While tools and visualizations exist, comprehending an unfamiliar code base remains challenging. Hence, software archaeology suffers from a considerable entry barrier as it requires expert knowledge, significant diligence, tenacity, and stamina. In this paper, we propose a paradigm shift in how legacy systems’ design knowledge can be regained by presenting our vision for an immersive explorable software visualization in virtual reality (VR). We propose innovative concepts leveraging benefits of VR for a) immersion in an exoteric visualization metaphor, b) effective navigation and orientation, c) guiding exploration, and d) maintaining a link to the implementation. By enabling immersive and playful legacy system exploration, we strive for lowering the entry barrier, fostering long-term engagement, strengthening mental-model building, and improving knowledge retention in an effort to ease coping with the increased number of tomorrow’s legacy systems.
This is the complementary conference talk/video:
Augmenting Metamodels with Seamless Support for Planning, Tracking, and Slicing Model Evolution Timelines
Extended journal version of our GPCE'19 paper "Automated Metamodel Augmentation for Seamless Model Evolution Tracking and Planning" (see beneath):
In model-based software engineering, models are central artifacts for management, design and implementation. To meet new requirements, engineers need to plan and perform model evolution. So far, model evolution histories are captured using version control systems, e.g., Git. However, these systems are unsuitable for planning model evolution as they do not have a notion of future changes. Furthermore, formally assigning responsibilities to engineers for performing evolution of model parts is achieved by using additional tools for access control. To remedy these shortcomings, we provide a method to generate evolution-aware modeling notations by augmenting existing metamodels with concepts for capturing previous performed and planned evolution as first-class entity. To provide a clear overview, we automatically generate a Gantt-style viewer for augmented models and capabilities to slice models for certain time periods. Our method enables engineers to seamlessly plan future model evolution while actively developing the current model state using a centralized access point for evolution. With the generated Gantt-style viewers and the slicing functionality, we enable engineers to inspect relevant model evolution while reducing model size and hiding unnecessary complexity. In our evaluation, we provide an implementation of our method in the tool TemporalRegulator3000. We show applicability for real-world metamodels and capture the entire evolution timeline of corresponding models.
ISA - Immersive Software Archaeology
My PhD project ISA is is a virtual reality software visualization project. Its goal is to foster the rediscovery of unfamiliar legacy Java software systems' architecture and design.
Long-living legacy software systems grow old over time in tact with engineers retiring or changing jobs and technologies becoming obsolete even though they are still in use. Software archaeology helps new generations of engineers to understand such legacy systems to enable maintenance and modernization. Yet, the code base is large, hard to navigate and incomprehensible. The project ISA will exploit immersive 3D virtual reality to increase the effectiveness of software archaeology. We will create a virtual reality representation of a software system that can be explored interactively, for example, a city with buildings, floors and streets representing modules, functions and dependencies. We will analyze system usage to guide through meaningful exploration routes and highlight particularly important system areas as targets. The project will be conducted by internationally recognized researchers from the ITU Copenhagen in collaboration with a world-leading Swiss visualization expert, a high-tech German startup and two Danish virtual reality companies. The project results have the potential to substantially advance practices in software archaeology and make the field more accessible to classically trained software engineers, which is fundamental for coping with a dramatically increased number of legacy systems in the future.
My work at ITU is supported by the DFF (Independent Research Fund Denmark) within the project ISA – Immersive Software Archaeology (0136-00070B).
PhD Student - IT University of Copenhagen (ITU)
I am a PhD student at the IT University of Copenhagen since January 2021 where I work in the computer science department.
Member of SQUARE Research Group
Three months prior to my PhD, I joined the Software Quality Research (or short: SQuaRe) group at ITU.
Consistency-Preserving Evolution Planning on Feature Models
In this paper, we present a method that enables to safely plan evolution based on an evolving feature model:
A software product line (SPL) enables large-scale reuse in a family of related software systems through configurable features. SPLs represent a long-term investment so that their ongoing evolution becomes paramount and requires careful planning. While existing approaches enable to create an evolution plan for an SPL on feature-model (FM) level, they assume the plan to be rigid and do not support retroactive changes. In this paper, we present a method that enables to create and retroactively adapt an FM evolution plan while preventing undesired impacts on its structural and logical consistency. This method is founded in structural operational semantics and linear temporal logic. We implement our method using rewriting logic, integrate it within an FM tool suite and perform an evaluation using a collection of existing FM evolution scenarios.
Automated Metamodel Augmentation for Seamless Model Evolution Tracking and Planning
In this paper, we present a method that allows to automatically extend any given model with the ability to keep track of its evolution:
In model-based software engineering, models are central artifacts used for management, design and implementation. To meet new requirements, engineers need to plan and perform model evolution. So far, model evolution histories are captured using version control systems, e.g., Git. However, these systems are unsuitable for planning model evolution as they do not have a notion of future changes. Furthermore, formally assigning responsibilities to engineers for performing evolution of model parts is achieved by using additional tools for access control. To remedy these shortcomings, we provide a method to generate evolution-aware modeling notations by augmenting existing metamodels with concepts for capturing past and planned evolution as first-class entity. Our method enables engineers to seamlessly plan future model evolution while actively developing the current model state, both using a centralized access point for evolution. In our evaluation, we provide an implementation of our method in the tool TemporalRegulator3000, show applicability for realworld metamodels, and capture the entire evolution time line of corresponding models.
DarwinSPL - Evolution-Aware Feature Modeling
DarwinSPL is a tool for modeling and analyzing evolving software product lines. It was started, developed and maintained by Michael Nieke at TU Braunschweig's ISF.
In 2019, I joined the DarwinSPL development team and started to implemented the concepts that we created in the LTEP project.
DarwinSPL can be downloaded from its Git repository!
LTEP - Long-Term Evolution Planning for Highly Variable Software Systems
LTEP was a research project funded by the German Academic Exchange Service (DAAD) and the Research Council of Norway (NFR).
Starting in 2019, it paved the way for a great collaboration between four researchers from Norway and three researchers from Germany (i.a., me), on different academic career levels from MSc students to PhD students, post-docs and associate professors.
The objectives of LTEP were:
- Strengthening / reinforcement of academic relations
- Complementary cooperative research work at a high academic level
- Qualification of young academics in an international environment
Kids at a Lake
Character on Bridge
DeltaJava - Delta-Oriented Programming for Java
DeltaJava is a programming language designed for the development of Software Product Lines consisting of Java code. DeltaJava implements the delta-oriented programming paradigm, i.e., code is encapsulated in delta modules which can add, remove, or modify functionality to and from an existing code base or other delta modules. Applying different sets of deltas thus results in different products.
DeltaJava can be downloaded from its website - tutorial videos included!
Research Assistant - TU Braunschweig
During my studies at Technische Universität Braunschweig, I was a research assistant for the Institute of Software Engineering and Automotive Informatics (ISF).