accuracy also add value. At the same time, this
heterogeneity of sources and types creates a number
of challenges associated with Big Data use in a Smart
City such as volume, velocity, variety, veracity and
value.
Powerful data techniques are needed, to allow
collecting, storing, analyzing, processing, and
visualizing vast amounts of city related data.
Handling highly variable and real-time datasets
requires new tools and methods, such as powerful
processors, software and algorithms, that go beyond
traditional "data mining" tools designed to handle
mainly low-variety, small scale and static datasets,
often manually. Key aspects such as real-time
analytics, low latency and scalability in processing
data, new and rich user interfaces, interacting with
and linking data, information and content, all have to
be advanced to open up new opportunities and to
sustain or develop competitive advantages.
Interoperability of data sets and data-driven solutions,
as well as agreed approaches are essential for a wide
adoption within and across city authorities and
citizens.
A great tool for policy making, decision support
and performance assessment in fields such as
environment, economic, mobility, are indicators and
composite indexes. The indicators allow better
understanding of smart city challenges by
stakeholders and highlight the effective policies, best
practices and reasonable decisions. The composite
indexes can be unambiguously undestanded by the
policy makers and easily communicated to the
general public (Bohringer, 2007). Both indicators and
composite indexes should be developed with a clear
vision of how they interact with each other, otherwise
the policy decisions could decrease the opportunities
for long-term sustainability (Mayer, 2008).
All these demand rethinking technologies around
smart city solutions and bring the main objective of
project “Big Data Innovative Solutions for Smart
Cities” (Big4Smart, 2018), funding by the National
Scientific fund of Ministry of Education and Science
in Bulgaria. The primary goal of Big4Smart project is
to develop methodology, implemented by an open
technological platform, that support making informed
and timely decisions on big data for building smart
cities. This paper proposes an architecture of the
technological platform for Big4Smart project that
provides a transparent and flexible performance
assessment of smart cities through a range of
indicators covering all city aspects such as living,
people, transport, etc. The indicators give an insight
into the extent to which the city is becoming
“smarter” and outline the driving factors for
sustainable development.
The purpose of the indicators directly influences
their selection. Since they are used for assessment of
cities’ performance and to inform policy at the city
level, it is important to define them in national
context, taking into account the national conditions
and priorities. In addition, the availability of data
sources is a critical issue for successful calculation of
indicators’ values. The required data is provided
primary at national level by variety of institutions
such as national statistical offices, ministries and
government agencies, non-government
organizations, etc. Thus, although the Big4Smart
methodology aims to provide a smart city evaluation
concept in general, its underlying technological
platform should be developed in national scope,
namely taking into account the Bulgarian context.
The rest of the paper is organized as follows. The
current state of the research on the problem area is
described in Section 2. The architecture of the
Big4Smart platform is described in Section 3. Section
4 is devoted on indicator classification schema,
adopted to the Big4Smart platform. Conclusions and
directions for future work are outlined in Section 5.
2 STATE-OF-THE-ART
Several indicator frameworks related to performance
evaluation of smart cities are developed within
European Framework programs. Their main
drawbacks could be summarized as follows:
Covering a specific city sector such as healthcare,
education, industry, etc.;
Assessment of current performance state without
any insight into progress to "smartness".
To the best of our knowledge there is no indicator
framework for evaluation of smart city performance
in Bulgaria. In addition, the proposed Big4Smart
platform aims to assess the progress of cities by
covering variety smart city dimensions in six thematic
areas: smart mobility, smart nature, smart living,
smart people, smart economy and smart government,
described further in Section 4.
2.1 State-of-the-Art at European Level
There are a lot of undergoing FP7 and Horizon 2020
projects and research initiatives related both to Big
Data and Smart Cities. Table 1 lists several ones very
relevant to Big4Smart research. It is advisable to keep
all the given values.