Best Practices and Methodologies to Promote the Digitization of Public Services Citizen-Driven: A Systematic Literature Review

: Governments at all levels have a mandate to provide services, protect society, and make the economy prosper. While this is a long-term goal, citizens are now expecting greater and faster delivery of services from government. This paper presents a systematic literature review of service digitization carried out by the governments of several countries, which was motivated by the lack of primary studies in the literature related to the identiﬁcation of the processes and methodologies adopted by these governments and private companies to provide their services to the citizen. This work also contributes to the identiﬁcation of best practices, technologies and tools used for the provision and evaluation of digitized services provided and how governments are evaluating the gains from digitization. These results of this systematic literature review serve as inputs to guide current and future research of the Brazilian Government in the construction of a digital platform for the provision of its services directed to the citizen, seeking to analyze their needs and improving the services currently provided.


Introduction
Service digitization has emerged as a way to provide more efficiency, effectiveness and quality [1] in government services, being able to reduce existing bureaucracy in the current processes [2].
Information and Communication Technology (ICT) is another/extensional term for Information Technology (IT) that stresses the role of unified communications and the integration of telecommunications (telephone lines and wireless signals), computers as well as necessary enterprise software, middleware, storage, and audio-visual systems, which enable users to access, store, transmit, and manipulate information. However, definition, as the concepts, methods and applications involved in ICT are constantly evolving on an almost daily basis. The broadness of ICT covers any product that will store, retrieve, manipulate, transmit or receive information electronically in a digital form, for example, personal computers, digital television, email, robots. ICT can help in this bureaucracy reduction, providing ways to simplify procedures and mechanisms, through, among other forms, routine automation [2].
These days, most governments have a renewed focus on citizen happiness and engagement, and a well-planned digital government environment offers greater opportunities for building collaborative and participatory relationships among all relevant stakeholders [3].
In the case of public services, there are attempts to make access universal, in other words, available to all citizens regardless of income, education level, geographical location or access conditions to technological resources [1]. Providing services under such conditions is a challenge for governments around the world. The major trends fueling the public sector are driven by rising citizen expectations, which in turn drives four key aspects: • Pressure to deliver for more consumer-like citizen services; • Need to refocus resources in areas that boost government program delivery and make it visible to citizens; • Drive to improve citizen outcomes and install a government culture of service excellence and accountability; • Necessity to diversify the economy, attract and nurture new businesses utilizing new business models under the umbrella of government as a facilitator.

•
Strengthening of public-private partnerships as a way of increasing access to digitized services.
Driven by these pressures, government objectives cannot be limited to just the introduction of digital technologies and process automation within departments. It goes far beyond that, requiring a focused effort on digitally engaging citizens to modernize the public sector as a whole.
A key measure of success by modern countries is the level of engagement that their people undertake with their government. As the OECD (Organization for Economic Cooperation and Development) [4] states, good decision-making requires the knowledge, experiences, views, and values of the public, and unless citizens themselves understand and are engaged in the decision-making, trust is easily lost.
There are several benefits to citizens driving public policy reform and modernization as part of a digital government transformation. Citizen engagement drives the success of e-government, or digital government, by increasing the acceptance and uptake with the government through digital channels. This helps departments scale up services while reducing cost without compromising sustainability. It improves governance and creates a more informed government. This marks the shift in viewing citizens as customers of the government rather than subjects, which dictates a higher degree of interaction and engagement.
Engaged citizens can make important contributions to policies and programs related to every aspect of city life and government services. It reinforces government success by introducing a critical and honest feedback mechanism, building public trust in their leadership [5].
With regard to Brazil, the government has sought to encourage its Agencies to transform their digital services for access, sharing and monitoring of information, registration of demands and requests for official documents. The main objective of the Brazilian Government is to have a Digital Government From Citizen-Centric To Citizen-Driven, modernizing all public services.
Since 2016, important decrees have been published in this sense, defining a Digital Governance Policy [6] and the Digital Citizenship Platform [7] in the scope of the Federal Public Administration.
The Digital Citizenship Platform [7] aims to broaden and simplify the access of Brazilian citizens to digital public services, including through mobile devices. The Federal Government Service Portal should be a single integrated channel for the provision of information, electronic request and monitoring of public services, whose objective is, in addition to providing practicality and agility for citizens and entrepreneurs, for digital services to reduce the cost to government by up to 97%.
It is expected that the reduction will eliminate the unnecessary commuting costs of the government service, as well as waiting time in the queues, possible printouts of certificates, and document endorsements. The actions of the Platform are aligned with the Digital Governance Strategy (DGS) [8,9] that will guide the actions of ICTs of the Brazilian Government until 2019.
It is necessary to identify tools that measure the reach of the services not scanned in Brazil, to assist in the implementation and expansion of the services provision. These tools can help to increase citizen participation in the use of current services and even in the development of new services. Tools for pricing the costs of all these operations, still need to be studied and/or even developed. This paper presents a systematic literature review about the digitization of Government services. Its main contribution is to identify in the literature how the governments of other countries are promoting the automation and digitization of their public services, as well as to present the best practices adopted for the process of government automation and digitization. In addition, it presents the registry of the technological solutions adopted in the processes used by success cases.
The remainder of this paper is organized as follows. Section 2 presents the research methodology adopted, the protocol and the result of the systematic literature review. In the Section 3 the results and the discussions are presented. Section 4 presents the proposed model. The conclusions and future work are presented in Section 5.

Research Methodology
The research methodology used in this study was the Systematic Literature Review (SLR) proposed by Kitchenham [10]. SLR is a way of identifying, analyzing and interpreting available evidence related to a particular research question, area or phenomena of interest [10,11]. Studies that contribute to a systematic review are called primary studies. A systematic review per se is a form of secondary study [10].

Systematic Literature Review
Systematic Literature Review (SLR) is a secondary form of study that looks to identify and analyze research relevant to a certain research question. Among its characteristics, we can highlight [10]:

•
It has a review protocol that is defined at the start of the research. This protocol defines the research questions to be approached, and which methods will be used during the research; • It proposes the creation of a well-documented research strategy. This strategy needs to be good enough to get the highest amount of primary studies in literature relevant to the topic; • It uses inclusion and exclusion criteria to evaluate the primary studies found.
During the SLR, the Planning, Conducting and Reporting phases of the results were followed [10,12,13]. The research protocol followed in this work is presented in Figure 1 with the phases and activities performed in each of the phases of the SLR. The flow between the activities performed occurred iteratively. The phases and activities include: • Planning: The planning phase aims to identify the real need, namely the motivation to execute a SLR [11]. It is composed of the main activities of defining the objective and preparation of the protocol that will guide the SLR in order to minimize biases that can be committed by the researcher [12]. As well as the evaluation of this protocol, which in this work was carried out with the protocol test in one of the databases chosen for performing the automatic search. • Conduction: During this phase of the SLR, the studies are identified through the application of the search strategy and selected according to the protocol defined in the planning phase. For the set of selected works, data are collected and synthesized in order to answer the research questions and thus facilitate analysis and synthesis for the creation of results [11].

•
Reporting Results: The last phase of the SLR is related to the documentation of the SLR, where the description of the results must be executed, the answers to the research questions prepared and the results disseminated to the potential interested parties [12].
The tool StArt (State of the Art through Systematic Review) was used to support the performance of the SLR, assisting in the planning and conduction stages of the Systematic Review Literature.
The SLR was carried out with the objective of identifying and presenting the best practices and technologies currently adopted in the automation and digitization processes of services, as well as presenting guidelines on how to include automated and digitized processes in Brazilian federal public services.

Research Questions
The research protocol of Figure 1 was defined according to the methods, technologies and useful mechanisms to promote the automation and digitization of services. Thus, the Research Questions (RQ) were defined, which are presented in the Table 1.

RQ Description
RQ.1. How to promote the automation and digitization of federal public services in Brazil?
RQ.2. How to include in the automation process and the digitization of public services the citizens and agencies that provide the services?
RQ.3. Which are the best practices adopted for the automation process and digitization of public services?
RQ.4. What technological solutions are adopted in the automation processes and digitization of public services?

Search Strategy
The search strategy involved the use of Automatic Search [14], which consists of searching through the Search String in the electronic databases, followed by the Manual Search [14], through which searches were performed for works in conferences, newspapers or magazines.
The Automatic Search was performed in the following databases: Digital library ACM; Digital Library IEEE Xplore; DBLP-Computer Science Bibliography.
The Manual Search activity was performed in the Annals of the Conferences and Periodicals specific to the e-government area, as presented in Table 2: The definition of the search String was prepared according to the set of criteria PICO [11,13,15], which consists of: P-population. The population corresponds to a specific role within the lifecycle of the research focus, an area of application, or even a specific group of the industry; I-intervention, delimits the research focus within a broader scope; C-comparison, identifies alternatives and compares with the delimitation performed in the intervention; and O-outcomes, lists what is intended to be achieved, measured, improved or affected in relation to the population.
Delimitation of PICO criteria for this work is presented below.
• Population: The defined population was the automation or digitization of services. To search the population, the keywords digitization, automation, delivery and service were used. • Intervention: The intervention aimed to identify and present the most relevant methods, technologies and mechanisms to promote the automation and digitization of services. For this, the following keywords were used: methods, technology and mechanism. • Comparation: The focus of the study did not cover comparative studies, so this technique was not used in the search strategy and in the formation of the search string.

Selection Criteria (Inclusion and Exclusion)
The following selection criteria were defined for the selection of primary studies:

1.
The paper must be available in the previously defined digital databases.

2.
The year of publication of the studies should be between 2007 and 2018. However, classical sources with definitions (books with classical concepts or pioneering articles) were also considered. The defined period of 10 years was identified as suitable for work selection, according to important research guides in the area of software engineering [11,13,[15][16][17][18][19][20]].

3.
The study must have been written in English or Portuguese. 4.
The study should propose or evaluate methods, technologies or mechanisms of digitization or automation of services.

5.
The work must relate to both services provided by governments, as well as to participation or realization by citizens. 6.
The work is classified as gray literature, that is, it is technical reports, preliminary studies, technical specifications, official documents of specific organs [11].
As criterion of exclusion of the studies was considered the non-fulfillment of some of the inclusion criteria, as well as: 1.
In the case of incomplete works -published as Short Paper.

2.
Do not present sufficient information to extract the expected data, thus impairing the quality or relevance of the work [16].

Quality Criteria
The evaluation of the quality of the studies identified after the execution of the search strategy allowed the selection of the most relevant articles to compose the SLR, being executed through the 4 stages of selection of studies defined by [14], which are presented in Figure 2. The stages adopted in the search strategy were:

1.
Execution of search strategy involving automatic and manual searches. Thereby, a preliminary list of studies is generated, with the help of the StArt tool, it was possible to discard the duplicate works.

2.
Identification of potentially relevant studies, based on reading the title and abstract. In this stage it is possible to discard studies that are clearly irrelevant to the research. In case of doubt about the permanence of any study in the SLR, the next stage assists in this definition.

3.
Reading of the introduction, methodology and conclusion of the pre-selected works, again applying the inclusion and exclusion criteria.
The papers that were selected in stage 3 should be read in full and the volume of articles resulting from this stage will be used to compose the SLR and support the answers to the research questions.

Evaluation of the Adopted Research Protocol
To finish the planning activity of the Systematic Review Literature, the adopted protocol was tested through the execution of a pilot in the Digital Library ACM. With the execution of this activity, it was expected to evaluate the reach of the search string, and the result obtained was considered satisfactory and no adjustments were identified to be performed in the defined protocol.
While conducting this SLR, search activity was documented to ensure transparency and enable readers to verify its completeness and comprehensiveness [10]. The activities are described in the next sections. The SLR process may be reproduced or audited, if necessary.

Selection of Primary Studies
The automatic selection process of the primary studies was started by executing the search string in the digital databases. The automatic search in the 3 bases defined results in a total of 727 articles, as shown in Table 3. It is important to note that only 6 papers were identified as duplicates, and the occurrence of duplicity occurred on the basis of Digital library ACM and Digital library DBLP. The Figure 3 presents the evolution of the steps adopted in the selection strategy, which were applied in the papers identified during the automatic search.
The manual search performed in the Annals of Conferences and Periodicals determined in Table 2 and also represented in Figure 3 (by green points) was performed through various combinations of the search string defined in the protocol. This variation of the String was necessary because the bases of the Conferences and Periodicals have a smaller volume of publications and using the complete String often no work was identified. The manual search resulted in a total of 56 articles (Figure 3), which followed the stages defined in the adopted protocol, adding 783 articles in stage 1 ( Figure 3). The evolution of the selection of these in the systematic literature review (SLR) is presented on the Table 4. After the final application of all stages of the work selection strategy, a total of 26 articles (Figure 3) were identified to be used in data extraction. The evolution of the resulting work at each stage of the paper selection strategy accumulated per year of publication is presented in Figure 4. According to Figure 4 it is possible to identify that the number of publications involving the subject digitization of services is in a phase of growing interest by researchers, with a considerable increase in the number of publications between the years 2016 and 2017.

Data Extraction
Data extraction began with the export of bibliographic files in the BibTex format originated with the execution of the search strategy. These files contained information such as: title of the work, authors, year of publication, classification of the document, place of publication, number of pages and abstract.
The summary was made available together with the BibTex file only in the IEEE Digital Library, in the other search sources, the abstract had to be added through the individual research of each work.
With the development of the work until reaching stage 3 of the search strategy, where it was necessary to download the papers for complete reading and finalization of the selection, data extraction was performed with the functionalities of "Study Data" and "Selection Data" of the StArt tool.
It was necessary to carry out the complete reading of the articles to finalize the final selection of studies to compose the SLR. "Data Extraction Form" functionality of the StArt tool was also used, where the contributions of the works were recorded, as well as the information selected to be inserted in the synthesis of the answers of the research questions.

Results
Applying the search strategy, we identified a total of 783 papers. This comprises 56 papers from manual search and 727 papers from automatic search ( Figure 3). Two researchers read title, abstract and keywords of the papers, and the application of selection criteria produced a list of 96 primary study candidates. Another researcher decided on disagreements in this task. The candidates' list was refined through the full papers reading and the application of exclusion criteria. As result of the whole screening process, depicted in Figure 5, this research identified 26 primary studies. The data extraction occurred in all 26 articles selected in the last step of the strategy defined in the protocol of this research. From the complete reading of these articles presented in Table 5 it was possible to answer the research questions. The deployment of government-digitized services requires more than technological sophistication, requires a shift in the mindset of public administration to citizen-centered service delivery [22].
The work presented by [21], highlights 5 key methods for the digitization of services by governments, being: 1.
All citizens should be taken into account by promoting reliable, innovative and easily accessible services for all; 2.
Efficiency and effectiveness must be a reality in the services provided, contributing to the high satisfaction, transparency and responsibility of users, relieving management and providing quality gains and resource savings; 3.
The services implemented must start with the essential and high impact for citizens and companies. In order to identify such services, citizens and society must be included in the process of definition of scope and design; 4.
Enabling elements should be added to services, enabling citizens and businesses to benefit from convenient, secure and interoperable forms of access; 5.
Participation in developing ideas and choosing priorities should be democratic, using tools for effective public debate and empowering citizens and society in decision-making.
These key methods can be followed by the Brazilian government in order to allow the expansion and improvement of the digitized services provided. Other factors that may contribute to this process are: • Analysis, measurement and quality assurance of the ways of making these services available. For this, the user's perceptions about technology, satisfaction and trust must be taken into account [26]; • Providing services tailored to the needs of each citizen, respecting their profile (which may be related to age group, educational level, economic situation and others) and from this determine the amount of information and the level of detail to be provided [37].
The choice of service delivery channels is another issue that should be widely evaluated by the Brazilian government to support the digitization of services.
Communication technologies have been evolving over the years, starting with traditional and personal communications, including options such as telephone and mail, reaching the use of the internet, social media and mobile phones with a wide variety of applications [44]. Artificial Intelligence techniques are also being inserted in this process, for example with the use of social and conversational robots that interact more and more with the citizens [44].
Currently, the most widely used means for delivering services digitized by governments and companies is the use of website portals, which deliver online services 24 hours a day in any part of the world, provided there is connection with internet [27]. Examples of services that can be offered by online portals are [27]: • Access by the agencies of requests for information or needs of registered services; • Requests for real estate or automobile registrations; • Certificates and school records; • Real-time monitoring by different bodies of citizen complaints (for example damaged roads, reports of violent crime or reports of missing children); • Intelligent monitoring of natural disasters such as floods and landslides.
Other channels for providing services to citizens are: • Mobile devices to access portals or service applications [27]; • Self-service kiosks that have the option of delivering official documents [25]; • SMS (Short Messaging Service) for the delivery of public services, mainly warnings and information, in order to maintain proximity, connectivity, interactivity and continuous communication with all citizens [23]; • Social Networks that has a fast and wide reach of the population when it is necessary to disclose urgent information. This channel can also be used to identify citizens' needs not formally expressed [24]; • Chat used as a way of asking the citizen's doubts about various issues [24].

RQ.2. How to Include in the Automation Process and the Digitization of Public Services the Citizens and Agencies That Provide the Services?
Deciding which services are to be deployed, identifying which services need improvement and finding out why some services do not have the expected volume of access are tasks that can only be performed if they have the joint involvement of citizens, society at large, public servants and decision makers of the provider of this service.
The inclusion of stakeholders in digitization is a good practice for the success of the process, since treating the citizen as a partner in government activities provides a number of contributions, such as: saving time, experiencing real need and great interest in achievement of positive results [5,30].
In addition, citizen participation enhances the transparency, confidence, acceptability and legitimacy of decisions taken by policy makers [28].
Some initiatives that seek for this greater participation of the citizen and of the own agencies in the process of automation and digitization of services are: • In addition to the application of technologies, it should be taken into account in the provision of digitized services 3 main categories: (1) the ability of decision-makers to communicate constantly with implementers in order to deliver as well as obtain the right information when needed; (2) competence of decision-makers to assign responsibilities to implementers in order to reduce bureaucracy and allow greater agility between processes; and (3) the ability to define clear rules in the provision and use of services, which should be widely disseminated to all stakeholders [32]; • The use of open data may be conducive to increasing the transparency of processes and can also be used to identify new demands for services to be made available. Some examples to achieve this increase in value for citizens can be: 1. Through the analysis of the questions answered by the citizens during the use of the services [33]; 2. Identification of the most accessed information [33]; 3. The mining of data to identify information expressed by citizens in non-official media, such as the use of social networks [28,33]; • The gamification techniques can be used to involve citizens in the process of ideas of new types of services, helping in the elaboration of new concepts of digital services or improvement of existing services [35].
In addition to involving the citizen in the participation of the development of services, it is also important to identify ways in which citizens are more interested in using these services. Some examples are:

•
Keep the information and forms of access centralized in a single point, in addition to automating and simplifying the processes in order to make the citizen more independent to meet their needs [2]; • Information portals, booklets or other means of disseminating knowledge should not be static, rather, they should be able to deliver personalized information to citizens with the volume of data and details appropriate to each profile [37]; • Realization of more investments in marketing, advertising and promotion of services, being through different channels and with various forms of access. This seeks to raise the level of awareness and knowledge of citizens regarding the services provided by the Government [28]; • Demographic and socioeconomic conditions such as gender, age, formal education, economic income and political attitudes are factors that must be raised and understood so that the services are adequate to the different profiles existing for citizens [31]. Systems and services should be prepared to have user-friendly interfaces, adapting whenever possible to the profiles that have been identified [28]; • Providing public infrastructures, accessible and prepared to support the services offered, in order to guarantee availability and avoid access problems [28]; • Provide complete and high quality systems and processes, solving the needs of citizens in their entirety [28]; • Provide security and privacy of individuals and their data that must be kept intact and confidential [28]; • Gamification parts of the systems and services to thus involve and motivate the users to adopt the new processes with greater interest [34].

RQ.3. Which Are the Best Practices Adopted for the Automation Process and Digitization of Public Services?
In the provision of digitized services, it is not enough to provide countless services without understanding the real needs of citizens and the factors that influence the use of this type of service.
Among the factors that are pointed out as essential for the interaction of citizens with the digitized services, one can cite quality, agility, privacy and security, all those present at each stage of interaction between the interested parts [26]. It is worth emphasizing that quality must be present in different aspects, such as: quality of the system, quality of service, quality of information, quality of content and product quality [26].
The work presented by Bertot et al [36] complements the list presented by Akram and Malik [26], of the essential elements to be evaluated in the implementation of digitized services, which are:

1.
Infrastructure: Digital infrastructure is a necessary prerequisite, including robust digital technology infrastructure within governments, between citizens and industry. Without connectivity, access to systems and service applications is not possible; 2.
Capacity: Different capacities, including organizational, human, regulatory, collaborative and other, must be present in all governments, industry, communities and citizens. These capabilities are needed to leverage the digital technology infrastructure and broadcast digital innovations; 3.
Ecosystems: Innovative services, empowered by governments, should be part of a broader social innovation ecosystem, facilitating cultural change to adopt a positive attitude towards risk and product acceptance; 4.
Partnerships: While governments may face challenges with their ability to innovate, they can take advantage of the innovative capabilities and resources of partners. Developing the capacity to partner with the private and non-profit sectors and engaging citizens in defining new services are important mechanisms for delivering innovative public services; 5.
Inclusion: If innovative services must be ubiquitous and benefit all, they need to be available and usable by everyone. Implemented innovations should ensure that all actors have the ability to use and benefit from these services; 6.
Value: Innovations must offer public value and be valued; 7.
Delivery Channels: Many factors, including age, preferences, digital literacy, infrastructure, among others, affect the acceptance of digital services and opportunities for citizens to get involved. Therefore, several service delivery channels are required for engagement as well as multichannel delivery strategies to decide the most appropriate channels for each service; 8.
Security: Digital service innovations can not be deployed without ensuring the security of interactions and stored content; 9.
Privacy: Security focuses on content protection, while privacy belongs to citizens' ability to opt out of digital public services. Innovations can not be mandatory, but citizens must retain the right to select the services they wish to receive, use or wish to engage with. For this to happen, privacy must be ensured; 10. Authentication: Secure and verifiable authentication is required, but we also need appropriate authentication measures to ensure that the recipients of the service are indeed recipients. This requires layers of security and authentication across all services.
Other guidelines identified with the systematic review of literature as best practices in the implementation of digitized services are: • Factors that may justify the low use of digitized services are the way services are delivered, trying to simulate processes that are already available, typically derived and conceived from human interaction, where citizen trust is generated from direct interactions with public officials. When developing services using ICTs (Information and Communication Technologies), it is important to keep in mind that access to a website or portal does not provide the same level of trust as personal services, so mechanisms that can help increase citizens' trust should be introduced into digitized services [38].
It is not enough to implement a large set of services, it is necessary to monitor the use of these services, measuring citizen satisfaction and identifying improvements to be implemented in order to increase the engagement and use of services [38].

•
Environments for the provision of digitized services must be formed by 3 layers, being: 1 a -Web portal through which the citizen will interact, including flexible and adaptable tools; 2 a -Electronic protocol system, which is an intermediate layer responsible for security mechanisms and infrastructure for the provision of services and 3 a -System itself, where the functionalities to be made available are developed, tested and put into production [1].
Organizations, including public and private, must create, maintain and follow strategic ICT planning to guide their processes, avoid unrealistic strategies with poorly designed action plans or lack of internal alignment [39].

RQ.4. What Technological Solutions Are Adopted in the Automation Processes and Digitization of Public Services?
The use of existing Information and Communication Technologies (ICT) is vital in the process of accelerating the digitization of services, providing services increasingly adapted to the individual needs of citizens, providing greater satisfaction and use of these services. This process is important for citizens, who will have access to a more convenient, preferable and economical form of interaction with public agencies. For governments, this approach is important because it allows for cross-departmental synchronization, decreasing queues, reducing response time and financial expenses [25].
New technologies arise at all times and are analyzed in order to identify benefits of their use in existing processes. One of the major concerns of governments and citizens' demands [27] is with respect to the security of the transactions and the data used in these operations. Some examples of innovative practices with respect to electronic government security are:

•
SecureGov is a mechanism that has been implemented in Korea's Public Information Sharing Center (PISC). This system uses a layered security structure with combined technologies, including a usage control scheme called Enterprise Digital Right Management (E-DRM) to prevent the illegal use and leaking of data, a counterfeit prevention technology using a 2-D bar code to prevent illegal data modification and a Public Key (PKI) scheme to ensure the authenticity of the data [27]. • A prototype is being tested by the government of India in that the proposal is an integrated digital signature approach based on cloud computing to enable electronic authentication and data security in the transaction phase of digitized services [42].

•
The Government of India also uses another mechanism involving the digital signature to perform authentication of the data through the temporary proxy signature, where the owner of the signature transfers the power of its use to a signatory authority during a specific period of time and any misuse of the resources is prevented through the signature key generation procedure [41].
• The government of Georgia has an exclusive department to deal with the cyber security of its digitized services, among its practices is the monitoring of the use of services and the volume of transactions carried out.
Governments also need to be concerned with mechanisms to prevent fraud in the use of digitized services, among the innovative technologies identified, we have: • The government of Greece uses an online system for requesting services by citizens where the processing of the orders made takes place almost completely in an automated way, to reduce response time and minimize the need for human intervention, with the aim of avoiding fraud at any stage of the request process [1].

•
The use of SmartGates, which are kiosks for citizens' recognition through the evaluation of biometric data and even the face [25] which are common at airports and customs for validation of documents such as passports, is already being tested by several governments, such as Russia, which in self-service kiosks allows the citizen to make requests for documents and makes their delivery using this technology [25].
Regarding the technological innovations that are being tested and/or used to support quality, agility and increased use of digitized services, it can be mentioned: • The use of social robots to complement government communication channels with citizens is the option that brings together artificial intelligence techniques allowing richer service experiences that increasingly resemble human experiences. The use of these technologies lowers the burden on the organization and its human agents [44].

•
The use of geo-visualization to aid in the understanding of data that has a spatial reference to them associated with technology that has been used to help citizens and rulers to more effectively understand information in a geographic environment and thus facilitate communication between these stakeholders for better decision-making. A simple example of the use of such technology is the decision to be made on a new cycleway to be deployed in a given city, with the use of geo-visualization citizens can suggest routes to be constructed [43].
Continued innovation in the provision of public services is essential to meet the diverse social needs, raising social aspirations, economic pressure and unequal conditions for the provision of public services within and between countries. The results of this systematic literature review allowed us to identify several Government initiatives with this intention and to establish a panorama for the needs of the Brazilian Government, considering the best practices that were identified [45]. In addition, a proposal for a model for the digitization of Brazilian public services was constructed.

Threats to Validity
We describe as follows the threats to validity of this systematic literature review, as well as mitigation strategies for each one:

•
Research questions: the defined questions might not have covered the whole digital government and digitization services area. Thus, one may not find answers to the questions that concern him/her. As we considered this a feasible threat, several discussion meetings with the research team were held to calibrate the systematic literature review questions; • Subjectivity in the study selection: we cannot guarantee that all relevant primary studies were selected. It is possible that relevant papers were not chosen. In order to mitigate it, we performed the automatic search, and complemented it by performing manual search to try to collect all primary studies in this field; • Subjectivity in the data extraction: during the data extraction process, the primary studies were classified based on our judgment. In order to mitigate this threat, the classification process was performed using peer review; • Repeatability of the systematic process: there is a risk involving the ability to replicate or extend this systematic literature review. This threat is mitigated through a detailed description of the systematic process in this work, since all details of the systematic literature review protocol were described. Moreover, we published the data extraction results on the Web as an additional source of information.

Proposed Model
With the accomplishment of the systematic literature review it was possible to answer the research questions that were elaborated to guide our research and to propose a digitization model to be tested by the Brazilian Government. Figure 6 presents the proposed model.
The model proposed to customize the services provided by the Brazilian Government needs to have the Process centered on the Citizen, where each phase represents the activities necessary to be executed. The first phase, for example, which is to customize it ( Figure 6-The goal is to understand citizen), requires the following activities/tasks to be performed:

1.
Map the stakeholders: Map the general outline and description of the different individuals, groups and organizations that interrelate, directly or indirectly, with each other.

2.
Identify the possible stakeholders: Conducting a survey or interviewing citizens in a busy location.

3.
Identify communication channels: Verify which communication channels will be used, and can be structured: surveys, interviews; formal unstructured: e-mail, chat; and informal: social networks.

4.
Identify needs: Map and classify quantitatively the priorities of services and/or functionalities to be implemented.

5.
Apply techniques to identify the profiles of citizens: Profiles related to age group, educational level, economic situation, among others, must be identified for delivery of the adequate volume of information. Profiles related to difficulty of access or deficiency (auditory or visual) should be identified to suit the way the service is delivered.

6.
Provide a tool to evaluate the services provided: Services must be continuously evaluated to identify changes or improvements to be developed, access below expected, as well as to perceive infrastructure or security problems.

7.
Apply improvements in services provided: Improvements or changes must be implemented to fit the perceptions of citizens. 8. Implement mechanisms to maintain and/or encourage the use of services: The citizen should be encouraged to use the services as if they were part of their daily life.
This model will be implemented in a federal government agency with the purpose of executing all activities of the customize phase, recording all the collected information, as well as the citizens' feedback regarding the proposed model. If the necessity for adjustments is identified at this stage, these adjustments will be made prior to the implementation of the complete model, in order to allow the other phases to be detailed and implemented with the aim to validate the model as a whole and especially the first phase that is important to understand the profile of the citizen who will consume the digitized services.

Conclusions
In this paper, a systematic literature review was performed to investigate the state-of-the-art in the digital government area. As the result of a combined automatic and manual search, 26 primary studies were identified. Four research questions of these studies were analyzed. The evidence from the research questions guided the identification of research gaps and incentives for future research.
The systematic literature review allows to find scientific papers on a particular subject and in this work it was identified several works related to the topic of service digitization. Among them, articles with the focus on Digital Government, main area of interest of our research.
From the articles selected in the last step of the review, it was possible to answer the research questions that were defined to guide this research and to identify the initiatives addressed by the countries that are at a more advanced stage than the Brazilian Government in the offer of its digitized public services.
Answering the research questions, it was possible to identify possible solutions to be used and/or customized by the Brazilian Government on how to promote the automation and digitization of its services. In addition, to validate the culture proposed by the Government that the citizen is part of the process, being essential its participation for the government to achieve a good and efficient digitization of its services.
This review also allowed to identify the best e-government practices currently used by other countries in their digitization processes of public services. These practices will be important in the choice of tools that will be adopted by Brazil in the process of establishing its Digital Citizenship Platform centered on the Brazilian citizen.
The technological solutions adopted in the digitization processes found in the literature will allow a reflection about the security mechanisms that the Federal Government should take into account when the Digital Citizenship Platform [7] to the Brazilian citizens, understanding the necessary actions to increase and improve the offer of digital public services.
It is well known that the digitization of public services requires several fronts and a comprehensive team in front of the process, with the purpose of offering quality services, safe and adherent to the needs of the citizen. Brazil is walking on this horizon and progress is being made in this direction.
It is necessary to propose a platform comprising all the necessary variables (phases and activities), with a coherent process to evaluate the maturity of the services and a correct pricing according to our scenario. Thus, this paper proposes from the answers of the research questions, a model of digitization of services centered on the citizen to the Brazilian Government with the tools and technologies used in cases of success in other governments. We plan to extend this study by undertaking a broader automated search for other systematic literature review about digitization of services centered on the citizen over the other time period.
As future work, from this systematic review, we will validate the service digitization model proposed in a Federal Public Administration Agency and make possible adjustments and/or improvements, in order to encourage citizen participation in the digital services offered.