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Corporate InformationResearch & Development

Photo: SHIMURA Akitoshi
SHIMURA Akitoshi
Senior Researcher

The public infrastructure of Japan is one of the foremost reliable system in the world. At Hitachi, aiming at establishing public-infrastructure systems that can flexibly handle unforeseen trouble and environmental changes as well as assure high reliably, we are developing "renovation technology."

To create public-infrastucture systems that can flexibly handle changes, it is necessary to find invariant "fundamental principles and general rules."

Future demands of public-infrastructure systems

Tell us about the environment surrounding public-infrastructure systems.

Photo: SHIMURA Akitoshi

SHIMURAThe reliability of public infrastructure in Japan is unrivalled in the world; for example, the power-failure rate is extremely low (i.e., 0.1 times per year), and the on-time-service ratio of the railway system is around 90%. Accordingly, Japan's public infrastructure has become just another part of our day-to-day lives. However, following the Great East Japan Earthquake in 2011, our frame of mind has changed.

At that time, we often heard two phrases, namely, "within expectation" and "beyond the limits of expectation." Public-infrastructure systems up until now have maintained extremely high reliability within expectation, and this was the objective of the public-infrastructure systems. However, it has become necessary to maintain high reliability in the case of emergencies too.

Moreover, as for development of public-infrastructure systems from now onwards, it is necessary to keep an eye on the global picture as well as the Japanese one. If a country changes, livelihoods and cultures will change too, and the structure of businesses concerned with public-infrastructure systems will change accordingly. Taking railways in Japan as an example, we see that lines, stations, and trains are all controlled and operated by a single railway company. However, in the case of railways in other countries, company A controls the lines and companies B and C operate and manage the trains, is commonplace. The structure of the business in the latter case is thus different. Public-infrastructure systems must thus be flexible and be able to handle both cases.

In other words, it has become necessary to improve public-infrastructure systems not from the viewpoint that "steady state is normal" (namely, a system operates as preplanned) but from the viewpoint that "change is normal" (namely, a system can respond flexibly to continuous changes in environments, structures, and so on).

Taking the viewpoint that "change is normal", we have started to develop "renovation technology" for making public-infrastructure systems applicable to environmental changes and cultures of various countries.

Figure 1: Changes in viewpoints regarding public-infrastructure systems
Changes in viewpoints regarding public-infrastructure systems

The word "renovated housing" is often heard, right?

SHIMURAYes, from the very beginning, the word "renovation" has been widely used in the construction industry. In contrast to "reform" (which implies on-the-surface refurbishment), "renovation" implies extracting a building frame, restoring it, and redesigning certain parts. Considering that the word "renovation" can also be applied to improvement of public-infrastructure systems in the same way as to improvement of buildings, we are using the name "renovation technology" to refer to the technologies to achieve that renovation. And the word "renovation" includes the meaning "re-innovation"—namely, coming up with innovations once again.

Does that mean extracting the structural framework of public-infrastructure systems?

SHIMURAYes. As for public-infrastructure systems too, we thought there are things that correspond to a structural framework—namely, things that haven't changed since the analog era. If we take railways as an example, we know that, in the old days, trains used to be controlled by hand signals, but nowadays, they are controlled automatically by control systems. Although the control means has switched from an analog to a digital basis, the act of controlling the train has not itself changed. In other words, as for public-infrastructure systems, there are physical phenomena that remain unchanged. And those phenomena become "fundamental principles and general rules" when systems are constructed. The techniques for uncovering those principles and rules related to public-infrastructure systems and for fundamentally reforming those systems are called "renovation technologies."

Figure 2: Renovation technology
Renovation technology

Extracting developers' minds from the source code

Tell us about renovation technology in detail.

SHIMURARenovation technology aims to fundamentally renew systems through three processes: "reform," "refine," and "renovation." These three processes are referred to as "R3". First, the "behavior" of a system, namely, its "functional capability," is extracted by the "reform" process. Then, by means of the "refine" process, the reasons those functions were created in the first place are understood, and fundamental principles and general rules are uncovered. Lastly, by means of the "renovation" process, the system is drastically renewed on the basis of those principles and rules. Now, taking the example of train operation control systems, I'll explain each of the three Rs in the following.

Figure 3: The R3 processes of renovation technology
The R3 processes of renovation technology

SHIMURAAs I mentioned above, the "behavior" (namely, functional capability) of a system is revealed by the reform process. That process is akin to the task of finding the "form" of a system at the time of development. As for a public-infrastructure system, since its number of functions increases as it is used over many years, its scale expands. However, the fundamental nature of the system itself doesn't change. For example, the software architecture of a train operation control system in current use hasn't changed that much compared to that at the time of development. So we thought why not reveal the fundamental principles and general rules associated with a system by uncovering the functions of a system at development time. Nonetheless, there are practically no remaining informational materials that clearly explain the foundation of specific functions. As a result, we initially set out to soundly look at the source code.

A train is a means of carrying people and goods. While we were looking at the source codes, we dug up what functions are required to achieve that means and how that functions behave. Considering every single "if" statement, we answered the questions, "Is it being used?", "Is it OK if it is missing?", and "What is it used for?" one by one.

That seems like really tough work, right?

SHIMURAIt was. Day after day in the development field, we were investigating the source codes. The work of digging up the past from source codes was arduous. In particular, as for the terminology used in the railway field, it was difficult dealing with so many specialized terms. When words we didn't understand came up, we had to stop investigating source codes and look up the meaning of the terms in question.

Among the three processes (3Rs) involved in renovation technology, "reform" is the most troublesome—as well as the most important. While we were performing the reform process, we gained knowhow about the system under investigation.

Figure 4: Overview of train operation control system
Overview of train operation control system

Discovering fundamental principles and general rules

The next process is "refine", right?

Photo: SHIMURA Akitoshi

SHIMURAThe "refine" process reveals fundamental principles and general rules associated with systems by answering two questions concerning the functions extracted by the "reform" process, namely, "Why does this function exist?" and "Why is it needed in this case?"

Although the behavior (i.e., functions) of a system is stated in a function-specification document, the grounds for creating those functions are not stated. Accordingly, by conducting interviews with the experts involved, we dug up what they were thinking at the time they created the functions.

Among our group, we call the task of unearthing what those experts were thinking "system archeology." That is because the task of digging up the thoughts of the people involved during the development of a system is akin to archeology.

Did the unearthing task go smoothly?

SHIMURAAlthough we asked the experts involved questions like "Why does this function exist?" and "Why does the system behave in such and such a manner?", we only got answers like "That function is a matter of course." and "That's just the way it is." in a manner that seems obvious to someone with knowledge of railways. All the same, by persisting with our questions, we started to understand the reasons were related to track topology, such as "It is because of this line policy." and "Lines branch at this point."

Thanks to the results of these questions, we realized that "The reason for the behavior is probably the track topology" and "The track topology and the function can be modelled by attaching some sort of correspondence between them." For example, when a train is running along a line, it stops in front of a signal and starts in front of a signal. Moreover, in front of a signal, there is a protection zone into which only one train can enter. In other words, the train runs on a line that is configured so as to combine physical restrictions with safety restrictions. This is the fundamental principles and general rules, and train can only run in accordance with restrictions based on that principles and rules. Given that fact, we thought that we could uniquely determine what functions are required by the line in question by suitably modelling the physical topology and constraint conditions based on those fundamental principles and general rules.

If the track topology is determined, the necessary functions will be determined too, right?

SHIMURAThat's right. In fact, we have completed the modeling of the track topology. We are currently investigating to what extent a system can be restructured. And while performing this investigation, we are pushing ahead with the renovation process, one of the "3R" processes. This is an approach that enables post-mapping of IT services (which use the latest information technology and operational information) to control systems based on fundamental principles and general rules.

Enhancing the quality of a infrastructure after completion of construction

What kinds of things will be done by the renovation process?

SHIMURAA scheduling diagram represents information concerning operation of train operation control systems. We are investigating whether simple control and mapping are possible by separating the control and the scheduling diagram and by modelling the diagram itself to a certain extent. Trains are then run in accordance with a plan referred to as an "scheduling diagram". However, the existence of a diagram on its own accord doesn't mean that control is possible (since the diagram and control must be thought of separately). In other words, "control" needs to be done whether or not a diagram exists (i.e., control shouldn't rely on diagrams). We think post-mapping of diagrams is the best way to handle train operation.

At present, each system is optimized for each customer. If a request from a customer to run a train according to a certain scheduling diagram is received, the train is run in accordance with that diagram. We thought why not create a system in the following form: "Train operation can now be controlled. Prepare a diagram that tells us how you want the train to run. When that is done, the train can be controlled in accordance with that diagram."

As explained previously, although it is natural in Japan that lines, stations, and trains are all controlled and operated by a single railway company, but it is not common in other countries. Since each railway company has a chosen scheduling diagram, we are thinking a structure that can easily comply with all various diagrams.

Figure 5: Mapping of control and scheduling diagram
Mapping of control and scheduling diagram

Surely this is "renovation" of systems, isn't it.

SHIMURAI think the difference between the current systems and systems in the past will not appear immediately. However, if we steadily continue these renovations, it will become possible to construct a system if we know the track wiring when a customer says, for example, "We want to create new routes and tracks." or "We want to build this station and layout lines like this."

In Japan, since we can assume users to a certain extent, scheduling diagrams suitable for those users can be configured. However, I don't think it is possible to comprehend utilization forms (like how users want to use systems) in countries where railways are underdeveloped. Accordingly, it is demanded that users' voices can be instantly fed back to the scheduling diagram, and the train can be promptly operated in accordance with that diagram. I want to create a world in which it is possible to quicken the development cycle for a system that incorporates citizens' needs in that manner.

I mentioned previously that the word "renovation" comes from the construction industry. According to the Ministry of Land, Infrastructure, Transport and Tourism of Japan, enhancing the quality of a building after completion of construction and improving its functionality is defined as "renovation." That is pretty match what we intend to do.

Renovation technology creates a new world

From now onwards, to what fields will you apply renovation technology?

SHIMURAWe intend to apply this technology to general public infrastructures like power supplies and water systems. Since there are the same kind of problems and the technologies which have been used for a long time, the chance to apply system archeology is there as well as railways. Having previously performed research on data-distribution technologies for vehicles, I am interested in "mobility". Accordingly, I want to take up public infrastructure not by thinking about it in terms of separate infrastructures based on cars and railways but by thinking of it as one big bundle that carries goods and people. For example, I want to apply renovation technology to "multi-modal urban transport;" namely, even if trains stop running to a destination, it is possible to get there by driving a car.

How are you thinking about future public-infrastructure systems?

Photo: SHIMURA Akitoshi

SHIMURAAll in all, public-infrastructure systems should be something taken for granted. However, if that consideration is taken to cover times of emergencies too, it is clear that Japan has a long way to go. What's more, in Japan, it is taken for granted that the train will come on time when we go to the station, that the electricity will come on when we return home, and that water will flow from the faucet when we turn on the tap. Although those services are taken for granted in Japan, in some other countries, such taken-for-granted lifestyles do not exist. Accordingly, people's sense of appreciation differs from country to country.

When Hitachi is constructing public-infrastructure systems in countries around the world, if we construct a system after listening to customers' needs and confirm what functions they need, it takes a large amount of time. Without having to follow that time-consuming procedure, we want to apply our proposed renovation technology to create a mechanism that allows us to construct systems while listening to customers' needs at local overseas sites.

That means visiting the country in question and visualizing what is required and finding what things have stayed unchanged in regard to that country. After that, working together with the people of that country, we can easily create the required systems and services. I think that mechanism will be necessary for creating the future public-infrastructure systems.

(Publication: August 2, 2013)


  • Publication: August 2, 2013
  • Professional affiliation and official position are at the time of publication.
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