The integration of water processes with information and communication technologies systems offers huge opportunities in terms of efficiency gains, improved security, and overall sustainability. However, as this new field of water management – often denoted as ‘Smart Water Network’ (SWN) – is evolving, there are many different vendors, technologies and business models in the market. This diversity overwhelms utilities and leads to excessive piloting of smart solutions, rather than to a general adoption. In order to exploit the full potential of these SWN solutions, standardized components guaranteeing interoperability and clearly defined interfaces as well as proper guidelines for implementing such solutions are needed. We will give a general overview of a SWN, the involved technological components, its interactions, and missing elements that are needed for an interoperable solution. We finish our contribution with a brief description of a structured process for planning SWN architectures.

INTRODUCTION

The water sector is in a transition phase, as information and communication technology (ICT) is intruding even into this rather conservative market. Water challenges and increasing costs put water utilities under pressure to adopt best available technologies. The integration of water processes with ICT systems combines classical water technologies with communication, Information Technology (IT), and advanced software tools.

The SWN is at a stage where the Smart (Power) Grid was 10 years ago. Many technology vendors address many challenges with very different technologies. This development results in an adoption deadlock, as the risks for a general adoption are considered to be too high. Utilities are overwhelmed by the sheer number of options. Instead, they either refrain completely from these technologies or pilot each SWN application. One key for bringing SWN technologies to the required acceptance is the introduction of a generally accepted framework. Such a framework helps design SWN architectures taking into account the particularities of such systems, which is especially reflected in the merger of automation systems with IT. A major design parameter is the concept of interoperability between elements of an architecture.

The paper is primarily directed to water utility managers and operators, as well as institutions and industry associations which work on SWN architectures and standardization. It is the authors’ intention to sensitize these groups to the subject of interoperability and to provide a framework considering all relevant facets.

The first section gives a brief introduction to SWNs and related challenges. The second section elaborates on the issue of interoperability, followed by the presentation of an architectural framework for SWNs. The paper concludes with a description of the main characteristics of the framework following case study scenarios of two SWN technologies.

SMART WATER NETWORK (SWN)

SWN (the integration of water processes and ICT systems is known by several terms. These include SWN, Smart or Intelligent Water Grid or Smart Water Management. In this paper, we will use the term ‘SWN’) refers to the adoption of advanced ICT by the water industry. The backbone is a fully integrated set of technologies (sensors, meters, actuators, data loggers, pumps, valves, etc.) communicating with each other and using information in order to automatically operate and control the system. Advanced software solutions further process collected data and ensure reliable and efficient management of water processes.

Today's water industry is struggling with several challenges including water scarcity, deteriorating infrastructure and stricter regulations (Maxwell 2013). Furthermore, costs are increasing, mainly driven by higher expenditure for energy and maintenance. For instance, in some regions in the United States, water infrastructure consumes up to 40% of the produced power (EPA). SWN technologies offer promising answers to these issues. Benefits include efficient resources allocation, energy savings, reduced non-revenue water, efficient asset management and maintenance. However, while there are specific SWN applications, which have already made their entrance into water networks, a fully integrated SWN has not yet been realized. Furthermore, the vast majority of these applications are deployed in pilot projects, rather than in large-scale implementations. The result is that the mentioned benefits are not fully exploited.

Potential of SWN technologies

Kingdom et al. (2006) estimated the yearly costs of non-revenue water at $14 billion. SWN technologies could decrease this figure dramatically by just introducing transparency into water distribution networks. Knowing the weak areas in water networks enables utilities to initiate appropriate countermeasures. Important cornerstones are wireless sensor network technologies, which are able to communicate over long distances. By using these technologies, utilities are now able to monitor their infrastructure even in areas which are hardly accessible, as no direct power supply is required. Once water flow and consumption are visualized, billing can be adjusted to the time-dependent usage behaviour of consumers and incentives for water conservation could be realized. Furthermore, knowing the demand side enables water utilities to adjust the pressure in water distribution networks according to the actual demand. Pressure management conserves the condition of water pipes and leads to energy savings, which can be realized by reducing the load and up-time of pumps (Fantozzi et al. 2009).

Data availability in SWNs

The collection of more and more data will lead to further improvements, as historical data help improve applied algorithms in SWN technologies. For instance, in order to set up an early warning system for the drinking water quality in a distribution network, an adequate baseline is key. The accuracy of this baseline depends on the available historical data. However, exploiting this potential requires seamless data flow from measurement devices through the automation system to analytical software.

SWN technologies are promising solutions for many water industry challenges. However, in order to develop the full potential of smart applications, different technologies have to work together in a fully integrated solution. Therefore, it is crucial to develop interoperable solutions and to accurately plan the implementation of SWN technologies.

INTEROPERABILITY – KEY FOR SMART WATER MANAGEMENT

IEC 61850 (International Electrotechnical Commission 2010) describes interoperability as the ability of two or more systems or components to exchange information and to use the information that has been exchanged. The Gridwise Architecture Council (Harbor Research Group 2009) further specifies this definition by the following characteristics: shared understanding of the exchanged information, agreed expectation for the response to the information exchange, and requisite quality of service including reliability, fidelity, and security. There are three principal types of interoperability: technical interoperability, semantic interoperability and process interoperability (Gibbons et al. 2007; Van der Veer & Wiles 2008). Technical interoperability focuses on the transmission and reception of data. Semantic interoperability is associated with the meaning of the data. Thus, interoperability on this level means that transmitter and receiver have a shared understanding about the data. Process interoperability refers to the ability to coordinate different information systems. It depends on successful implementation of technical and semantic interoperability.

Reaching a state of interoperability in a system requires input and commitment from a majority of its stakeholders, as generally accepted standards have to be developed and implemented. However, from an individual point of view, it might be rational to insist on proprietary solutions. First movers may be motivated to protect their products or services by deliberately excluding interfaces which would allow other technologies or vendors to tap on. This can result in a vendor or technology deadlock for the end-user. In the long term, however, such a strategy may compromise these enterprises. They might not be able to benefit from new developments and innovations in the respective field and, hence, face a risk of being outdated by the market. Ultimately, interoperable technologies and applications foster market penetration (e.g. Kim & Nam 2004).

Standards for more interoperability

Interoperability is often related to standards, as these contain information, processes and guidelines, which determine and organize a smooth data flow within a system. However, due to the complexity of cyber-physical systems, which consist of different technologies and components from different vendors, a comprehensive standardized interoperability reference architecture is required, rather than a single standard. An example for Smart (Power) Grids is the seamless integration reference architecture for interoperable communication IEC 62357.

The benefits of interoperable systems

Besides seamless data exchange and usage, interoperability offers several advantages, which are well documented in other industries (Harbor Research Group 2009). The benefits include lower transaction costs, lower maintenance costs, lower upgrade costs, and lower installation costs, as well as reduced risk of vendor lock-in and reduced negative effects of vendor bankruptcy (Arthur 1989; Walker et al. 2005; Lewis 2012).

Lower upgrade and installation costs are achieved by reducing the integration effort, due to the ‘plug and play’ ability of interoperable technologies (Ownes 1998). Moreover, utilities do not rely on a specific vendor, but have more options, as standardized information allows more suppliers to offer their services. It also reduces the risk of vendor lock-in and the effects of vendor bankruptcy. Furthermore, interoperable applications are a strong driver for innovation and help exploit the full potential of technology. Especially for small and innovative companies with specialized solutions, it is easier to enter the market, as standardized interfaces and interchangeable components lower the effort for implementing new solutions. This also fosters competition, which leads to more innovation and higher quality. A good example is Android, an operating system and software platform for smartphones, tablets and notebooks, which was initially developed by Google, but is open to applications developers. Today, Android runs on almost 80 percent of the global smartphone shipments (IDC 2013), and attracts innovative application developers.

Interoperability in SWN – current status

Interoperability in SWNs has not been realized yet. While there is a huge amount of literature (e.g. Gungor et al. 2011; Wang et al. 2011; NIST 2012) discussing interoperability issues in Smart (Power) Grids, accompanied by industry standards, which actually ensure interoperability throughout the systems (e.g. IEC 61850, ZigBee, Common Information Model), there are only a few activities addressing interoperability in SWNs (e.g. Hauser et al. 2013). Existing literature mainly focuses on specific sub-systems (e.g. Dzemydienė et al. 2008) rather than on the whole water distribution network.

Industry associations, such as the SWAN Forum (SWN Forum, www.swan-forum.com), are only just starting to put effort into the promotion and development of the concepts and standards for interoperability in SWNs. Nevertheless, the current situation requires a tool for the water industry to develop such standards. This paper provides a framework that covers all relevant aspects to develop inoperability standards and structures of SWNs.

ARCHITECTURAL FRAMEWORK FOR SWN PLANNING

An architectural framework addresses what it means to define and document an architecture. It provides a basic structure of important aspects, a communication tool, methods and common vocabulary (Schönherr 2006). The architecture itself is about the structure of systems or enterprises, their constituents, and how the different parts fit and work together to fulfil a specific purpose.

The proposed framework provides the basic structure of a SWN, including all relevant aspects, and supports the development of individual SWN architectures. Standardization bodies and industry associations can use it to identify standardization needs. For water utility managers and operators it serves as a starting point to build their specific SWN architecture.

SWN architectural framework – structure

Figure 1 shows the architectural framework (European Standardization Organization 2012; Burrows 2013). It combines the water lifecycle, which is presented by its five steps: source, treatment, distribution and storage, end-user, and wastewater reclamation and reuse, with six levels representing all components of a SWN and their hierarchical structure in terms of data flow.

Figure 1

SWN framework.

Figure 1

SWN framework.

Many different technologies are integrated in SWNs. The hierarchical structure of SWNs, which is represented by the levels, was introduced by the SWAN Forum (Burrows 2013) with the intention to have a better understanding of how these technologies interconnect and also to create a common vocabulary for SWNs.

The lowest level represents sensing and control devices in the field, followed by the collection and communication levels. This level includes technologies and devices, which are used to store and transmit data to the upper levels. Two-way communication also allows commands to be sent from the upper levels to control devices. The data management and display levels contain hardware and software, which enables aggregation and further processing of data as well as human–machine interaction. Typically, this is performed using a supervisory control and data acquisition system (SCADA system). On the data fusion and analysis level, software tools are used for network optimization or other purposes that require sophisticated data fusion and analytical algorithms. The enterprise level at the top of the structure is related to administrative purposes. Table 1 shows an exemplary compilation of hardware and software that are used in SWNs allocated to the respective hierarchical level (Burrows 2013; from own research).

Table 1

Technologies used in SWNs

LevelTechnology
Physical Pipes, valves, pumps, bulk meter, water treatment plants, wastewater treatment plants, wells 
Sensing & control Analytical sensors, smart water meters, flow logger, acoustic logger, acoustic correlators, remote terminal units, programmable logic controllers, remote pressure valves 
Collection & communication Data concentrator, power line carrier, RF (radio frequency), cellular network, fibre optical cable 
Data management & display Databases, GIS, SCADA, remote control, meter data management 
Data fusion & analysis Advanced pressure management, predictive maintenance, supply and demand forecasting, operation prioritization 
Enterprise CRM, enterprise resource planning, balanced scorecard 
LevelTechnology
Physical Pipes, valves, pumps, bulk meter, water treatment plants, wastewater treatment plants, wells 
Sensing & control Analytical sensors, smart water meters, flow logger, acoustic logger, acoustic correlators, remote terminal units, programmable logic controllers, remote pressure valves 
Collection & communication Data concentrator, power line carrier, RF (radio frequency), cellular network, fibre optical cable 
Data management & display Databases, GIS, SCADA, remote control, meter data management 
Data fusion & analysis Advanced pressure management, predictive maintenance, supply and demand forecasting, operation prioritization 
Enterprise CRM, enterprise resource planning, balanced scorecard 

The four layers in Figure 1 reflect the need for technical, semantic and process interoperability. Technical interoperability takes place at the component and communication layer, semantic interoperability is considered by the information layer, and the application layer provides a platform for process interoperability. Interoperability within an underlying layer enables flexibility on the next higher layer.

The component layer includes all physical and virtual components, meaning hardware and software that are part of the respective SWN technology. Furthermore, depending on the scope of the analysis, additional components, which are only indirectly related to the application, can be added to the layer: for example, other measurement devices that deliver data to the system, but are not a specific part of the SWN technology in question. These components are also reflected at the upper layers, serving as the basis for the analysis of the layers above. However, the application layer considers processes only, and therefore does not include these components. The communication layer hosts communication protocols and mechanisms that are required to exchange information. Together with the component layer, the communication layer provides the required perspectives and content to realize technical interoperability, as these layers comprise the components and processes used to send and receive data. The information layer requires standards and methodologies that define the meaning of data; hence, it reflects the need for semantic interoperability. The application layer provides a platform to visualize and analyse required processes that lead to process interoperability. Therefore, it shows all involved parties, their functions, and how they are connected. A party is each organization, entity or individual which is part of a SWN technology (e.g. control centre, remote service provider).

SWN architectural framework – application

Analysing a certain SWN application starts with a specific description of the case study scenario. The next step is to visualize the scenario at the component and application layer. This is followed by showing the exchanged information and how the information is structured and modelled. The last step is to define communication mechanisms and protocols at the communication layer. Once the case study is represented in the framework, the user is able to analyse the application regarding different aspects.

EXAMPLE SCENARIO

In this section, we briefly discuss the applicability of the framework and how it could be used to analyse a certain scenario. We use here a simplified advanced metering infrastructure (AMI) case study scenario, also referred to as smart water metering, and a NRW management case study.

Advanced metering infrastructure

AMI uses a fixed communication network that provides the ability to transmit data between smart water meters at the customer site and a water utility. It enables water utilities to remotely access the meter, in order to request information and also to control it. In order to run efficiently and interact with the existing system, the implementation of an AMI has to be planned properly. Processes have to be adjusted and a suitable technology has to be identified. The framework considers all relevant aspects from an ICT point of view.

In this case study scenario, the AMI consists of smart water meters, data collectors, geographic information system (GIS), a fixed communication network, and a customer relationship management system (CRM system). The smart water meters are deployed in the distribution network and measure the consumer's water consumption. The data are then transmitted to a data collector, which serves as gateway between the metering devices in the field and the CRM of the water utility. The GIS adds information about the location of meters and provides a human–machine interface. The CRM system combines the consumption data with information about the customer and water tariffs. It then sends bills and information about the consumption back to the customer, automatically. GSM communication technology enables the communication within the AMI. This case study is visualized within the proposed framework in Figures 2(a) and 2(b).

Figure 2

(a) Visualization of simplified case study scenario: component (left) and communication layer (right). (b) Visualization of simplified case study scenario: information (left) and application layer (right).

Figure 2

(a) Visualization of simplified case study scenario: component (left) and communication layer (right). (b) Visualization of simplified case study scenario: information (left) and application layer (right).

The above-mentioned components of the AMI are mapped into the component layer and build the baseline for further analyses of the case study scenario (Figure 2(a), component layer). In this case, we want to know which communication protocols (Figure 2(a), communication layer) can be used to send and receive data. Furthermore, it is of interest which data formats are supported by the protocols (Figure 2(b), information layer), in order to enable the basic functionality of the AMI (Figure 2(b), application layer). Based on this information, a water utility is able, for instance, to evaluate and select appropriate technology. With respect to interoperability, a utility can define different scenarios taking into account future applications, in order to investigate how the AMI can be extended or upgraded with other technologies. This helps define future compatible SWN strategies.

Non-revenue water management

The intention of the second scenario is to show the importance of considering interoperability while planning the deployment of SWN applications. NRW management requires a sophisticated network of different sensor technologies (pressure sensors, flow sensors, etc.) equipped with the ability to communicate with processing devices, such as SCADA systems or other, distributed control systems. Based on this information, analytical tools and hydraulic models are used to detect leakages in the distribution network and other sources of NRW. In order to have a smoothly functioning system, the various technologies have to be able to exchange data reliably and efficiently. This is at risk if, for instance, the solution deploys components such as pressure sensors and flow sensors from different vendors, who use different technologies to communicate with a data concentrator. Often this is necessary, in order to get the best available technology for the planned SWN. However, this may result in higher integration effort and transaction costs on the higher layers, as protocols have to be identified and deployed, which support the communication technology of both vendors. At least two different communication protocols would be required on the communication layer, causing more issues on the information layer. According to the communication protocol, data need to be modelled in a certain way to satisfy specific requirements on data size and format. This may lead to system failure or exceeding integration effort. Therefore, it is imperative to visualize and analyse the potential SWN application using a structured framework as the presented architectural framework.

CONCLUSION

The deployment of SWN applications requires detailed planning. Key for safe, reliable and efficient implementation and operation of SWN applications is interoperability. However, required standards are only partially available, which makes it even more important to design and plan SWN applications in a structured way, in order to ensure reliable, secure, safe and long-term operation.

The proposed framework provides the water industry with a structured and comprehensive concept that allows an organization to visualize and analyse its conception of a SWN, and therefore helps identify gaps and map its solution into the bigger picture, the SWN. This paper is also intended to lay the foundation for the development of corresponding standards.

While the framework mainly addresses technology which is required for a specific application, utilities need also to consider their strategy and management, and organizational structure, as well as the involvement of other stakeholders.

Strategic decisions, whether they are made on a corporate or business level, are meant to have a long-term impact on an organization's future development in many different ways (Foss 1997). Resources allocation, reputation, and culture are just some examples. Eventually, strategic decisions determine the success or failure of an organization. Against this background, organizations need to have a clear and sound SWN strategy, in order to tackle the challenges coming along with SWN integration. Furthermore, SWN applications require high management skills, as they include innovative and advanced technology, involve multiple participants, and introduce change and new processes. At the same time, an organization must not lose sight of quality, reliability, and efficiency while implementing SWN solutions. Hence, management systems and policies, considering these issues, need to be established, applied, and continuously aligned and improved. The implied change also requires adjustments to the organizational structure of a utility. However, the alignment of an organization's structure is a ‘[...] dynamic process of adjusting to environmental change and uncertainty – of maintaining an effective alignment with the environment while managing internal interdependencies – is enormously complex, encompassing myriad decisions and behaviours at several organisation levels’ (Miles et al. 1978). Therefore, it is important to follow structured and transparent processes during this change.

Finally, utilities need to consider the needs and requirements of their stakeholders, including investors, society, regulatory authorities, vendors, and customers, as well as their employees. Considering all different interests is a huge challenge for organizations, but is an important part of achieving good performance and competitive advantage (Heugens et al. 2002).

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