Model-Driven Engineering (MDE) has been shown to increase productivity and reuse and it has significantly enhanced important aspects of software engineering development such as consistency, maintainability and traceability [5]. MDE is therefore increasingly applied to larger and more complex systems. However, the current generation of modelling and model management technologies is being stressed to their limits in terms of their capacity to accommodate, in an agile way, collaborative development, efficient management and persistence of large models ( larger than a few hundreds of megabytes in size) . Thus, recent research has focused on scalability and flexibility across the MDE technical space to enable MDE to remain relevant and to continue delivering its widely recognized productivity, quality and maintainability benefits. The MONDO [1] project proposes to look into the scalability issues for MDE in order to give more flexibility in processes and to help into the agile definition and management of large models. The purpose of this paper is to provide a description of the challenges targeted by three of the industrial demonstrators that will be utilised to evaluate the capabilities of the MONDO technologies. The selected demonstrators are depicting typical MDE issues found in industry and describe the the benefits to be achieved in the selected scenarios.
The Use Cases that will be described herewith are the following: • Use Case for Modelling Tool domain.
Use Case for the Offshore Wind Power domain.
Use Case for Open-BIM Construction domain. In the next sections we briefly outline the challenges tackled by the MONDO project. We then describe three of the MONDO case studies and summarize the general feedback received from the three industries on the expected benefits to be put in place within the different contexts to achieve better flexibility during engineering and storage of large models. Finally, the paper is concluded along with plans on our future work.
Typically, achieving scalability involves being able to construct large models and associated DSLs or meta-models in a systematic manner; enabling large teams of modellers to construct and refine large models in a collaborative manner; advancing the state of the art in model querying and transformations tools so that they can cope with large models (of the order millions of model elements); and providing an infrastructure for efficient storage, indexing and retrieval of such models [5]. In particular, the maintenance and manipulation of large models unique scenarios addressed by a novel class of model transformations (MT) able to extend the capabilities of traditional MT approaches is under study within the MONDO project [13] and a prototype tool supporting scalable concrete visual syntax enabling the rapid construction of Domain Specific Languages (DSLs) with built-in capabilities to navigate, explore and abstract large models is foreseen and under study by the project.
The MONDO research roadmap towards achieving scalability in model driven engineering is described in [4] and briefly summarized in Figure 1. The project builds on MDE research issues aiming at dealing with industrial scale models that need to be persisted in a way that allows for their seamless and efficient manipulation [6][7], often by multiple stakeholders simultaneously and will tackle scalable queries and transformations, scalable DSLs, scalable collaborative modelling [10][11] [12] within scalable model persistence [6]. All the project advances will be reported within the main project web site at [1] for the whole project duration and all technologies developed by research partners will be released as open-source software under EPL [9]. As such, industrial partners within the project and outside it will be able develop proprietary extensions on top of this infrastructure without having to open-source them.
As part of the MONDO project, this paper looks closely into the needed efficient and flexible engineering, storage, indexing and retrieval of large models within three different industrial case studies selected to evaluate the project results.
SOFTEAM aims at applying scalability in MDE technologies within the SOFTEAM Modelio [2] modelling tool. Modelio is an open source modelling tool, providing support for many kind of modelling e.g. UML2 modelling, Enterprise Architecture modelling, Business Process modelling, and SOA modelling. The MONDO technologies are expected to make possible to enhance Modelio capabilities in an agile way and to allow it to manage very large models by gaining speed in the overall design carried out. In particular the production chain that includes, the DSL engineering, the DSL persistence, the model (conforms to a given DSL) engineering and the model persistence, that is currently in place within Modelio and the Eclipse Modeling Framework (EMF) [14] world is considered too much rigid and constrained by MDE users e.g. modellers, architect and developers.
The MONDO research and results will be key to meet the increasing need from SOFTEAM customers to support a more agile production chain that considers larger and larger models, and larger teams of developers. SOFTEAM will evaluate the MONDO improvements through an modelled application called Voyages Discount. This modelled application uses TOGAF modelling [3] which aims at improving business efficiency ensuring consistent standards, methods, and communication among enterprise architecture professionals.
The model has been chosen since it provides an industrial business process that required multiple stockholders communications to be completed where the modelling flexibility provided within MONDO will be helpful.
Currently the Modelio Teamwork Manager feature endows Modelio with a distributed collaborative modelling environment through a Subversion (SVN) repository. The model fragments [8], composing the Modelio project, are managed by Modelio Teamwork Manager and the enhancement of an improved collaboration environment will be very helpful in increasing productivity.
In Table 1 we present and summarize the expected targeted flexibility benefits and we consider in particular the need to reduce the time to complete the production chain above mentioned by means of structured EMF modularity and collaborations. This scenario focusses on the comparison of the query facilities and performances provided by both Modelio and MONDO frameworks. In the MBE approach, queries are often defined and performed to extract specific and relevant information from model. Modelio store offers a set of predefined scripts among thus the "Simple Statistics Reporting" script provides model statistics on objects present under selected element. This latter will be used as reference to compare both technologies in terms of querying.
technology will improve the Modelio querying facilities to better meet end user's needs in terms of performance (time and memory). A methodology whereby the performance of model queries can be systematically evaluated, and relevant performance predictor metrics can be identified is under study within MONDO [15]. More advances in this direction are also under study within [10]
MONDO technology is designed to support collaborative domain specific modelling for offshore wind turbines. Modelling tools will enable engineers to specify concurrently control systems of wind turbines and to share different specifications (model versions). This is expected to raise productivity during the development and customization of software for wind turbine control systems.
Wind turbines are complex systems composed by a set of physical subsystems. Different subsystems must work in a coordinated manner to transform wind energy into electrical energy. The purpose of a wind turbine control system is to supervise and control all those subsystems for their correct operation.
The Wind Turbine Control System Modelling Tool is a tool that the engineers use for specifying behaviour of the system that will control the wind turbine. Software code responsible for turbine control will be generated automatically from models. Control system development entails collaboration between engineers of different disciplines. Engineers of each discipline have different skills and they develop specific-parts of the wind turbine subsystems. Consequently, model specification implies the use of collaborative modelling tools. Moreover, since wind turbines' control models are large and complex, modelling tools should be scalable and provide agile mechanisms for model development (i.e. advanced queries, load-on-demand, partial load of models, etc.).
Wind Turbine Control System Modeling Tool has been developed based on existing Open-source Eclipse modeling technology. Unfortunately, existing modeling frameworks in which tools are based are not conceived to be used in an agile and collaborative manner. This is the case of the design of a wind turbine in which several engineers collaborate together step by step to define, integrate and validate models incrementally that form subsystems and then complete systems. In contrast to the work process described above, existing tools are conceived for a single engineer to work on a complete specification, preventing collaboration beyond the tool and the engineer. MONDO pursues to expand existing tools to support such collaborative modeling of teams of engineers working together. MONDO collaborative tools are expected to foster agility and collaboration in the modeling of wind turbines.
Results obtained on the MONDO Project will be the key to provide collaborative modelling tools enabling to turn the wind turbine design process into a more agile and flexible process. MONDO Project will enable to add new features to the modelling tools such as model edition, partial load of models, advanced querying capabilities, etc. Additionally, technology developed within the MONDO Project will support modelling from mobile devices. It will allow performing modelling activities also in environments where the conditions are not bests (in-situ maintenance of the wind turbine). This scenario is focused on the design of wind turbines' control systems. Several system engineers participate at the same time on the specification of wind turbine control system. Generally, each system engineer focuses in one subsystem and specifies the control of the subsystem. All those parts together specify the behaviour of the control system that is responsible to control and supervise the wind turbine.
Technology provided by MONDO will provide mechanisms that allow working concurrently on model elements. This will provide the flexibility for different modeling engineers to work at the same time on different subsystems or even on the same subsystem. As a result, this will ease teamwork when modeling a complete system. Apart from improving communication among engineers, it will favor an early identification of potential design flaws. Scenario 2: Partial load and load-ondemand of models related to subsystems This scenario is focused on the wind turbine commissioning process in which different physical subsystems (or sets of subsystems) are commissioned separately. This entails a scenario that from the view-point of system control, only a fragment of the whole model must be taken into account. System engineer only MONDO technology will allow system engineers to work only with specific parts of the model, providing features that allow partial load and load/unload on demand of parts of the model where different subsystems are specified. MONDO will provide needs the part of the model concerning to the subsystem. Therefore, system engineers involved on the subsystem commissioning must be able to work with a partial view of the whole model, having the ability to load and unload models fragments concerning to subsystems or parts of a subsystem. technology to enable a team of engineers to work on parts of models that can be validated partially. Enabling partial work will make the process more agile and flexible.
This scenario is located on the installation and maintenance activities performed within a wind farm. Often during these activities, wind turbine control systems require small adjustments (i.e. modify parameters' values or activation/deactivation of noncritical control algorithms). These adjustments will be performed using handy devices. However, these changes imply also (i) re-generate code for the control system and (ii) add the new model version to the repository. MONDO technology will provide engineers solutions to perform installation and maintenance activities of the wind turbines within a wind farm. These solutions should support modelling from lightweight devices such as mobiles or tablets. In this way, these solutions will facilitate fieldwork where commonly conditions are not good.
Besides Offshore Wind Power domain, IKERLAN-IK4 also plans to use technology developed within the MONDO Project on other domains such as transportation and capital goods.
A Building Information Model (BIM) is an instance of a populated data model of buildings that contains multi-disciplinary data specific to a particular building, which it describes unambiguously. BIM offers easier use of interoperable industry software tools, fewer errors and omissions, and time and cost savings that can cumulatively result in earlier building delivery. It can facilitate discussion, checking, analysis and communication about a project much earlier and in much clearer and precise terms than standard practice.
The IFC (Industry Foundation Classes aka Information For Construction) is the neutral and freely available specification (model) to describe, exchange and share information typically used within the building and facility management industry sector. As such, the IFC provides an Open-BIM as any single vendor or group of vendors does not control it, is openly accessible and used free of charge, and it is a standard de facto (in industry) and de jure (ISO 16739). BIM is a key enabler for Model-Based Engineering in construction-related ICT industries. ICT solutions for construction industries take advantage of MBE methods and practices to properly manage and exploit BIM models. The key solution to take advantage of MBE in BIM is the so-called Model Servers. Model Servers are a technological concept that was coined by the AECO software industry that designates a specialised ICT solution capable of providing BIM capabilities and services. A Model Server provides supports for modelling, storing, sharing, inspect, visualise, and operate BIM models.
Model Servers of today are generically using the Open-BIM IFC model. An Open-BIM/IFC Model Server is thus a data repository/store with supporting services that provide multi-user access, storage and management, and allow the use of the IFC data model as the underlying representation structure (schema).
A BIM-IFC data model of a not-so-complex building comprehends a huge number of modelling elements (to the millions scale). A comprehensive building information model enclosing all the building disciplines can rapidly go from few millions to many dozens of million modelling elements. Moreover, BIM-IFC data models are shared (serialized) using the text-based ISO10303 STEP Part#21 representations that rapidly escalate file sizes to many Megabytes to Gigabytes. The trouble is that today's breed of Model Servers exhibits problems in presence of big-to-huge BIM data models. Tools considerably degrade performance in presence of large-size BIM models (i.e. with some few millions of modelling elements) or simply "break" in presence of huge-size BIM models (in the scale of tens of millions of modelling elements). This led to very inefficient solutions for BIM-based collaboration like sharing partial models done by construction project designers and engineers that then requires time consuming model aggregation by some person ("model coordinator") and make it difficult for model users (model designers/engineers but also model clients) to get a comprehensive integral view of the model (building or set of buildings in a landscape).
The idea is for MONDO technologies to be able to take charge of addressing the performance and scalability issues of BIM data models that are presently dealt directly by its users (designers, engineers). The vision is that of a solution that enables an efficient management and exploitation of BIM large-to-huge-scale data models by both using best-of-breed MBE solutions and incorporating AECO domain knowledge for the best possibly experience and performance. Quantity take-off's (QTO) is a key process in construction. QTO are a detailed measurement of the materials needed to complete a construction project. These measurements are used to format a bid on the scope of construction. Estimators review drawings and specifications to find these quantities, which is a very time consuming, and erroneous process. BIM provides a direct way to extract the quantities of a building. It is done using a complex query to the BIM model.
On huge BIM data models performing QTO is a nontrivial task due to the complexity of the query and need to traverse the whole of the data model. The scenario tests then the ability of MONDO to report out of large-to-huge data models using complex queries situations. [10] [11] [12]
The case studies and evaluation scenarios selection presented herein was performed during the first ten months of the MONDO project (with a total duration of 30 months). As a general conclusion from the use case and scenario descriptions and the subsequent requirement gathering and prioritization phase form industry, it is believed that adopting MONDO technologies will bring benefits to the current software development processes used by all the involved industries, helping designers to work with large models.
In particular the MONDO technologies are expected to enable the Modelio tool to provide scalability in modelling, being able to construct large models and to enable large teams of modelers to construct and refine large models in a collaborative manner. Moreover, MONDO technologies will provide a solution for collaborative modelling within modelling tools to specify control systems for wind turbines. In this way these modelling tools will support features that ease collaboration. Finally MONDO technologies will be utilized within all the three case studies in the context of large model transformations. More specifically being able to generate documentation and to apply transformation on large models have been found as key aspects of scalable Model-Based Engineering.
The MONDO technologies evaluations within is planned for the end of second year of MONDO Project (October 2015). These will be both a qualitative and quantitative evaluations aimed at assessing the usefulness and ease of use when actually performing scalable modelling on real case studies through supporting tools.
The research leading to these results has received funding from the European Community Seventh Framework Programme (FP7/2007-2013) under grant agreement no FP7-611125. We would also like to acknowledge all the members of the MONDO Consortium for their valuable help and in particular Scott Hansen (The Open Group), and Dimitris Kolovos (University of York) for their support in the case studies scenarios and expected benefits definition.