NTT DATA’s Traceability Tool Platform helps in Realizing Mazda’s ‘Sustainable’ Future Goals

Overview Traceability between deliverables of model-based development provides quality and accountability while satisfying functional safety standards

Advanced digitization as well as the evolution of safety technologies continue to make engine control software larger, more sophisticated, and more complex. In order to adhere to the changing times and to continue the development of engine control software without compromising quality and speed, Mazda renewed its development method, which had been in use for 30 years, to the model-based development. Besides, the traceability between deliverables of different phases of the development process enables a platform that provides quality and accountability and satisfies functional safety standards such as IEC61508 and ISO26262. Moving beyond the domain of the engine, Mazda plans to implement traceability in the development of other domains, including the chassis and ADAS (Advanced Driver-Assistance Systems).

Background and issues: Introduction of model-based development Renewal of the conventional development method to the model-based development to improve overall efficiency and reduce costs

The brand slogan of Mazda, "Zoom-Zoom", represents its passion for continuously creating cars that provide "fun and exhilarating driving experiences". In 2007, Mazda had announced its long-term vision of technology development named "Sustainable Zoom-Zoom" that signified a breakthrough combination of driving pleasure, environmental technology, and safety performance". In August 2017, Mazda announced a new long-term vision of technology development named "Sustainable Zoom-Zoom 2030," which represents its goal of resolving issues from three viewpoints: the earth, society, and people by the year 2030.

The effort of achieving good balance between consideration for the global environment and comfortable driving led to the materialization of a new technology named "SKYACTIV TECHNOLOGY," which was announced in October 2010. A case in point is the "SKYACTIV-G", a new-generation, high-efficiency direct-injection engine that was mounted on the Demio /Mazda2, launched in June 2011. It reached a high compression ratio of 14.0, the first in the world for a mass-production gasoline engine. This engine also achieved a 15% improvement in fuel economy and torque as compared to existing engines, which opened a new door for the automobile industry. As a result of all the successful changes, Mazda gained worldwide attention, and has been ranked overall number one for five consecutive years up to 2018 in the "Fuel economy trends report", which is announced every year by the EPA (Environmental Protection Agency of the United States).

SKYACTIV Technology

However, the development of such a next-generation engine did not come easily and involved unimaginable difficulties. Michihiro Imada, General Manager of Infotainment and Control Model Development Department, Integrated Control System Development Division of Mazda, says, "In the conventional development, we iterated trial-and-error cycles with prototype engines and the ECU (Engine Control Unit) that controls the engines, while conducting simulation. With the improvement of driving and environmental performances, engine control software’s size had increased exponentially in 20 years from 1990 to 2010 and became 100 times larger. SKYACTIV-G, for example, has several tens of thousands of program variables and about 100,000 parameters, which would be about 10,000 pages if printed. In order to continue the development of the engine control software, which has become so sophisticated and complicated, without compromising quality and speed, we needed to fundamentally renew the conventional development method. We therefore turned our attention to model-based development."

Model-based development, in general, is a simulation-based method of developing control systems using a control model and a control target (plant) model. The control target has been expanding to the entire vehicle due to the complexity of automobile systems, and Mazda ultimately wanted to develop everything by simulation. Under these circumstances, Mazda extended the definition of model-based development to all the development that uses simulation involving not only control-target models but also existing CAE (Computer Aided Engineering) models.

Thus, Mazda made a bold decision to renew its entire development method that was in use for the last 30 years. Thanks to the bold move, Mazda realized the highly successful SKYACTIV TECHNOLOGY with the shift to model-based development.

Michihiro Imada
General Manager of Infotainment and
Control Model Development Department,
Integrated Control System Development
Division of Mazda

Factors for Selecting NTT DATA Availability of a tool that was flexible, customizable, and compatible with tools used internally

One thing that Mazda learned through the development of SKYACTIV-G is the importance of traceability. The traceability between deliverables of different phases of the development process not only provides quality and accountability of the large-scale engine control software, but also plays an essential role to meet functional safety standards such as IEC61508 and ISO26262. With this background, Mazda started to evaluate the traceability tools in 2012 and introduced products of large overseas vendors in consideration of support for control models, their compatibility with development tools, as well as the cost and support system. In two years, however, Mazda felt the limitations of those tools in practical use.

Mr. Imada says, "Because of the characteristics of traceability tools, we knew right from the beginning that it would be necessary to customize one of these tools. During the trial, we found that not only these tools had many defects and bugs, they also had low usability. Tools should not force the user to think about how to use them but should instead make life easier for the user with high usability. To our disappointment, at that time, every product was created by adding a traceability feature to an existing tool, such that they lacked uniformity in functionalities and usability as a tool. Though these shortcomings might be tolerable in small-scale development, our plan was to increase the number of users to several hundred soon. So, we decided to reconsider the overall strategy for traceability tools rather than invest further for more customization."

Under these circumstances, Mr. Imada stumbled onto "ZIPC TERAS" - a traceability tool platform provided by CATS Company, Ltd. of the NTT DATA Group in February 2014.

"On the recommendation of a team member, I participated in a reporting conference held before the official release. In addition to compatibility with control modeling tools such as MATLAB/Simulink and Stateflow, it provided intuitive operability that could only be achieved by a traceability-specialized tool, which was close to what we were seeking. While many vendors were based in overseas locations, the vendor of ZIPC TERAS was based in the same country, had an established track record, good reputation, and trust in the market. For customization, I could expect flexible support and good communication that are unique to domestic vendors. I felt we could make it work with ZIPC TERAS," says Mr. Imada.

Thus, Mazda introduced ZIPC TERAS on a trial basis in November 2014.

Introduction of ZIPC TERAS Smooth introduction followed by the construction of an optimum environment and support for customization

During the trial period of ZIPC TERAS, CATS provided seamless support with documentation and lectures. For the full-scale operation of the tool, Mazda provided its own training in the company based on the knowledge acquired during the trial, so there were not many queries at the start of the full-scale operation.

The introduction process was very smooth. Mr. Imada says, "Besides system construction, CATS provided full support to import the existing deliverables into ZIPC TERAS, for which I was very grateful. CATS's support was very helpful, enabling our development department to focus on their essential operations."

While existing hardware was used in the trial, NTT DATA helped renew the hardware environment including servers for the full-scale operation, to allow ZIPC TERAS to exert its full capability.

Mr. Takamasa Suetomi, Staff Manager in Infotainment and Control Model Development Department of the same division, says, "With the appropriate support of NTT DATA, we were able to build an ideal infrastructure, including the server specification and the server-client communication environment to manage the enormous amount of documents. We felt secure with NTT DATA because of their wide experience in large IT system projects and their first-rate track record and knowledge."

Mr. Suetomi continues about the customization and support system, "After NTT DATA and CATS entered our development office and conducted detailed interviews about our design procedure and issues, they made a proposal on the tracing unit and the procedure. This contributed to the construction of an optimum environment that suited our various operations. On the other hand, there were some other issues and points to review, such as too much of Mazda's customization that necessitated modifications on ZIPC TERAS every time an interoperating development tool was upgraded. However, they gained trust from the people in the field through their attitude of not just selling products but working together to customize them. Currently, we share our five-year plan with NTT DATA and CATS to work together to solve issues, including the design of the server environment, to prepare for future increase of documents."

Takamasa Suetomi
Staff Manager in Infotainment and
Control Model Development Department,
Integrated Control System Development
Division of Mazda

Solution Used: ZIPC TERAS
Tool platform that ensures and supports traceability between deliverables and documents. The tool can be used for not only software but also for various operations.

Effects and Future Landscape Increasing domains of ZIPC TERAS, while pursuing "driving pleasure,  environmental technology, and safety performance"

Mazda started full-scale operation of ZIPC TERAS in March 2017. The number of users now (February 2018) exceeds 300, and about 35,000 deliverables have been incorporated into ZIPC TERAS. While working on remaining functional and non-functional issues, Mazda is aiming to apply the tool to all departments by 2020.

“A breakthrough combination of driving pleasure, environmental technology, and safety performance" of a vehicle was made possible not just by the engine but also by multiple domains closely related to one another such as the chassis and ADAS. I want to increase the domains of ZIPC TERAS so that all processes and deliverables starting with requirement specifications are associated with ZIPC TERAS," says Mr. Imada.

He continues about the effects of the introduction of ZIPC TERAS, "When we adopted the model-based development for SKYACTIV-G, we were able to reduce bugs of engine control by 60%. Detailed verification of effects brought by traceability is yet to be done, but we expect that the other bugs to be reduced, because associating development phases from upstream to downstream helped us locate incomplete requirement specifications and/or later change requests."

Mazda is now launching an innovative effort of using AI in model-based development with the Mazda Co-Pilot Concept (concept of human-centered autonomous driving), seeking to resolve issues of Earth, Society and People through the charm of cars - "driving pleasure”. As part of this effort, Mazda is participating as an advisor in the development of the core technologies of next-generation artificial intelligence and robots promoted by JASA (Japan Embedded Systems Technology Association).

NTT DATA as a whole is going to provide full support for Mazda's efforts through different IT tools such as ZIPC R&B - a rule-based platform for the development of knowledge-type AI.

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