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    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Optimization and Post-Optimization Analysis of the Personnel Structure of Local Self-Government Bodies to Improve the Reintegration of Veterans⋆</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Taras Cherna</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Tetiana Shestakevych</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Lviv Polytechnic National University</institution>
          ,
          <addr-line>Lviv</addr-line>
          ,
          <country country="UA">Ukraine</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>This paper addresses the critical issue of veteran reintegration into civilian life, focusing on the optimization of human resource policies within local self-government bodies in Ukraine. Leveraging integer programming and post-optimization sensitivity analysis, the study aims to enhance the efficiency of veteran support services. A mathematical model is developed to optimize the staffing levels of veteran assistants and social workers within a local community, using GEKKO, a Python-based optimization tool. Parametric sensitivity analysis, employing the "One-Factor-At-a-Time" approach, is used to evaluate the impact of employee efficiency on optimal staffing solutions. The results demonstrate that the efficiency of social workers is a more sensitive parameter, highlighting the importance of their professional development and resource allocation. This study underscores the significance of sensitivity analysis in integer linear programming for identifying critical parameters and improving the overall effectiveness of social services management, ultimately contributing to the successful reintegration of veterans.</p>
      </abstract>
      <kwd-group>
        <kwd>eol&gt;veteran reintegration</kwd>
        <kwd>post-optimization analysis</kwd>
        <kwd>sensitivity analysis</kwd>
        <kwd>integer programming1</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>After completing military service, which requires adaptation to extreme conditions, veterans face
the challenge of reintegrating into civilian life. Reintegration is a multidimensional and long-term
process that involves physical and psychological recovery, social adaptation, and professional
realization. The success of this process largely depends on the support of family, the community,
and society as a whole. However, the key role is played by the state.</p>
      <p>Effective reintegration of veterans is not only a social responsibility of the state but also a
crucial factor in ensuring social cohesion and economic development. The state possesses the
resources and mechanisms to create a favorable environment for veterans' return to civilian life.
However, ineffective or insufficient government policies can significantly complicate this process.</p>
      <p>One of the key elements of reintegration policy is the human resource potential of local
selfgovernment bodies, which work directly with veterans and their families. Optimizing the staffing
of these bodies enhances service quality, ensures an individualized approach to veterans' needs,
and accelerates their social adaptation.</p>
      <p>Therefore, studying the role of state institutions in the social reintegration of veterans and
improving the human resource policies of local self-government is a significant contribution to the
development of the state support system for veterans, strengthening social inclusion, and
enhancing overall societal well-being [1].</p>
    </sec>
    <sec id="sec-2">
      <title>2. Optimization of Management Processes</title>
      <p>For Ukraine, ensuring an adequate standard of living for veterans is of utmost importance today.
This entails not only restructuring the departments that provide relevant assistance but also
enhancing the efficiency of their staff. Achieving this requires a strategic approach to optimizing
human resources and adapting management processes to properly address the specific needs of this
crucial category of citizens. Effective human resource management is a key factor in the
comprehensive administration of both operational and administrative processes [2].</p>
      <p>Opportunities for improving personnel management in local government departments will be
examined using the example of one of the territorial communities in Lviv Oblast—Davydiv Village
Council of Lviv District, Lviv Oblast, with a population of over 20,000 people. As veterans return to
their communities, the Davydiv Village Council has recorded a growing number of inquiries from
both veterans themselves and their families. Most of these requests relate to assistance with
processing social benefits, consultations on pension entitlements, opportunities for retraining or
acquiring new education, as well as issues of rehabilitation and free medical treatment. The scope
and nature of support largely depend on the veteran's status—whether they are simply recognized
as a combatant or have acquired a disability due to military service. Families of veterans also
frequently seek help in resolving household issues.</p>
      <p>Typically, a veteran first contacts the local Administrative Services Center (CNAP), where,
depending on the nature of the request, either a veteran’s assistant or a social department worker
assists them. The latter primarily provides social support in addressing everyday issues.</p>
      <p>As of July 6, 2024, Cabinet of Ministers of Ukraine Resolution No. 779 has come into effect,
introducing the position of veteran’s assistant within local government bodies. This resolution
defines the veteran’s assistant as a specialist who helps veterans reintegrate into civilian life and
access their entitled benefits and services.</p>
      <p>Thus, the process of handling inquiries from veterans and their families, as well as addressing
their requests for household assistance, involves two categories of employees: veteran’s assistants
and social workers. The specific nature of this activity within the village council will be formulated
as a task of optimizing the staffing structure of local government departments.</p>
    </sec>
    <sec id="sec-3">
      <title>3. The Problem of Optimizing the Staffing of Local Government</title>
    </sec>
    <sec id="sec-4">
      <title>Departments</title>
      <p>Based on the analysis of job responsibilities and workload of veteran assistants and social workers,
it can be generalized that on average, a veteran assistant processes 10 requests per week related to
document support and 1 request concerning household issues. In contrast, a social worker handles
1 request for document processing support and 5 requests for household issues per week. Also,
among the veteran assistant`s activities, there is a participation in internships or training programs
to update their knowledge on available opportunities for veterans. However, such training is not
mandatory for social workers. When evaluating the effectiveness of a veteran assistant’s work, the
Starosilska Village Council emphasizes the need for at least one veteran assistant on staff. Suppose
that each week, the social department of the village council receives at least 25 requests for
document processing support and 35 requests for assistance with household issues. It is necessary
to determine the minimum staffing levels, i.e., the number of veteran assistants and social workers
required to ensure the timely processing of all citizens' requests. To do this, we will build a
mathematical model for the corresponding problem, and since the solution involves determining
the number of employees, this problem falls under integer programming.</p>
      <p>Let x be the number of veteran assistants, and y be the number of social workers. We will
convert the problem's conditions into a tabular</p>
      <sec id="sec-4-1">
        <title>Then, the integer programming problem can be written in the form (1)-(3)</title>
      </sec>
      <sec id="sec-4-2">
        <title>Minimize</title>
      </sec>
      <sec id="sec-4-3">
        <title>Under conditions</title>
        <p>
          F = x + y ,
10x+ y⩾25
y+ 5y⩾35
x⩾1
(
          <xref ref-type="bibr" rid="ref1">1</xref>
          )
(
          <xref ref-type="bibr" rid="ref2">2</xref>
          )
x , y⩾0, x , y∈ Z (
          <xref ref-type="bibr" rid="ref3">3</xref>
          )
        </p>
        <p>
          To solve the integer programming problem (
          <xref ref-type="bibr" rid="ref1">1</xref>
          )-(
          <xref ref-type="bibr" rid="ref3">3</xref>
          ), we will use GEKKO — a Python package for
machine learning and solving integer and mixed optimization problems [3]. It is integrated with
numerical solvers for linear, quadratic, nonlinear, and mixed-integer programming problems, as
discussed by the authors in the work [4] in the context of nuclear waste recycling optimization.
        </p>
        <p>
          Thus, the solution to problem (
          <xref ref-type="bibr" rid="ref1">1</xref>
          )-(
          <xref ref-type="bibr" rid="ref3">3</xref>
          ) can be formulated as follows: to successfully process the
volume of requests received by the social department, its staff must consist of at least 2 veteran
assistants and 7 social workers
        </p>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>4. Post-optimization analysis of the problem</title>
      <p>The formulation of the staffing optimization problem for local government departments as an
integer programming problem not only allows for finding the optimal solution but also enables
post-optimization analysis, or sensitivity analysis, to investigate the impact of changes in the initial
parameters on the result.</p>
      <p>
        For linear programming problems, sensitivity analysis may involve determining the type of
constraints, finding the range of changes in the objective function coefficients, and determining the
value of resources. However, for integer programming problems, applying these approaches may
only provide approximate results, or the results may be difficult to interpret in the context of the
problem. To perform sensitivity analysis for the integer programming problem (
        <xref ref-type="bibr" rid="ref1">1</xref>
        )-(
        <xref ref-type="bibr" rid="ref3">3</xref>
        ), we will use
the parametric method, as described by the authors in [5] for analyzing the optimal size of solar
panels. By applying the parametric method, we will assess the stability of the optimal solution and
identify the parameters that most significantly impact the results. We will assume that stability
refers to the ability of the optimal solution to remain unchanged or to change only slightly when
the input data is altered.
      </p>
      <sec id="sec-5-1">
        <title>The sensitivity analysis will be conducted in three stages [6]:</title>
      </sec>
      <sec id="sec-5-2">
        <title>1. Identify the model parameters that will be subject to analysis.</title>
        <p>2. Compute the solutions to the corresponding integer programming problem with the given
parameters.</p>
        <p>3. Analyze the impact of each parameter on the model based on the computed indicators and
their visualization.</p>
        <p>
          The parameters for analysis will be selected based on the following considerations. The input
data for the problem (
          <xref ref-type="bibr" rid="ref1">1</xref>
          )-(
          <xref ref-type="bibr" rid="ref3">3</xref>
          ) is structured in a table on Figure 1: it includes the productivity of
specialists — the number of requests processed per week — as well as the number of various types
of requests received by the social department. For this problem, the number of requests received by
the social department is an uncontrollable parameter, meaning it cannot be influenced. On the
other hand, the input parameters, which denote the number of requests processed per week by an
employee, can be adjusted up to a certain limit, so these values will be analyzed in the parametric
analysis. The variability in the number of tasks performed may reflect the change in work
efficiency due to acquired experience and, as a result, the improvement in employee qualifications.
        </p>
        <p>We will use the "One-Factor-At-a-Time" approach [6], where only one parameter is changed
during modeling while the others remain constant. We will investigate the impact of changes in
the number of tasks performed by social workers on the optimization results. We will make two
assumptions.</p>
        <p>1. The effectiveness of the assistant's work is constant, meaning the coefficients for the variable
x will remain fixed, while the effectiveness of the social worker's work will vary between 1 and 15
tasks per week.</p>
        <p>2. Additionally, we will assume that a social worker cannot perform more than 16 tasks per
week in total, combining both types of tasks, due to the time-consuming nature of these tasks.</p>
        <p>
          In Figure 4, we present a heatmap of the results for calculating the optimal number of staff for
different parameters—the number of tasks a social worker completes per week. The element (
          <xref ref-type="bibr" rid="ref1 ref3">1,3</xref>
          ) of
this heatmap matrix contains the value "13 (2;11)", which can be read as "at least 13 employees are
needed to handle the requests (2 veteran assistants and 11 social workers), provided that a social
worker performs 1 document processing request and 3 social assistance requests per week." The
GEKKO package was also used to solve the respective tasks. On the heatmap, results that are
intentionally impossible are omitted: for example, the cell (10,10) should contain the optimal
number of workers for the condition where a social worker can complete 10 document processing
support cases and 10 household issue cases per week.
        </p>
        <p>Similarly, we will investigate the impact of changes in the number of tasks performed by the
veteran's assistant on the optimization results. Figure 4 presents a heatmap illustrating the results
of calculating the optimal number of staff members for different values of the number of tasks
performed by a veteran's assistant per week.</p>
        <p>The results exhibit a certain degree of symmetry. As illustrated in the heatmap in Figure 3, the
number of employees decreases across the columns from left to right as the number of tasks
performed increases. A similar downward trend in the number of employees can be observed
across the rows in the heatmap in Figure 4.</p>
        <p>The next step is to analyze the results obtained from Figures 4 and 5 to assess which data set
indicates greater sensitivity of the studied parameter. To do this, we will calculate the standard
deviation [6] across the rows and columns for each data set. We will compare the computed values
— for the data set with a higher standard deviation, we can conclude that the values in this set are
more spread out around the mean, meaning that the data variation is greater. This parameter is
critical and requires more attention. The calculations were performed using Python's numpy and
matplotlib.pyplot libraries. Computed numerical data are at Figure. 5, and Figure 6 presents a
visualization of the computed standard deviation values.</p>
        <p>As seen from Fig. 6, the standard deviation values for the results of the parametric analysis of
the social worker's performance are higher, which we take as an indication of greater sensitivity of
the studied parameter to the optimal solution. Thus, to improve personnel management in local
government departments, all other things being equal, it is advisable to focus efforts on increasing
the efficiency of social workers, for example, by ensuring their professional development,
improving the material and technical base, etc. Another conclusion from the results of the
postoptimization analysis may be that the veteran's assistant effectively performs his/her work, and if
there are a sufficient number of such specialists, veterans' requests will be processed in a timely
manner.</p>
      </sec>
    </sec>
    <sec id="sec-6">
      <title>5. Conclusions</title>
      <p>Sensitivity analysis in integer linear programming problems is an essential tool for assessing the
critical parameters of a problem. For the formulated problem of optimizing the staffing of
departments of local government bodies involved in meeting the needs of veterans, we studied how
changes in employee effectiveness impact the size and composition of the minimum staff required
for the timely processing of requests.</p>
      <p>In this case, the input parameter "number of requests" is not an object of sensitivity analysis.
Instead, parameters related to the number of tasks performed by employees can be analyzed in
post-optimization research. A parametric method based on the "One-Factor-At-a-Time" principle
([6]) was used for such an investigation. The sensitivity of each type of worker's effectiveness (the
number of tasks performed) on the optimal solution was analyzed.</p>
      <p>From the analysis of the computed standard deviation values, we can conclude that the
effectiveness of the social worker is a more sensitive parameter, which should be considered when
organizing the work of the social department. Taking the results of such analysis into account can
be used to improve the allocation of human resources, predict potential changes in workload, and
increase the overall effectiveness of social services management. The results can also be used for
adjusting workforce recruitment plans, ensuring their training, and rationally distributing
responsibilities among employees.</p>
    </sec>
    <sec id="sec-7">
      <title>6. Declaration on Generative AI</title>
      <sec id="sec-7-1">
        <title>The authors have not employed any Generative AI tools.</title>
      </sec>
    </sec>
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