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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Modeling and Analyzing Information Flow in Development Teams as a Pipe System</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Jil Kl u¨nder</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Oliver Karras</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Nils Prenner</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Kurt Schneider</string-name>
          <email>kurt.schneiderg@inf.uni-hannover.de</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Leibniz University Hannover, Software Engineering Group</institution>
          ,
          <addr-line>Hannover</addr-line>
          ,
          <country country="DE">Germany</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>-Teamwork is essential for developing valuable software. Working in a team requires an appropriate information exchange among team members in order to avoid loss of information. In order to analyze and improve information flows, it is recommended to observe the information exchange in a team. We propose an approach for modeling the information flow of teams as a pipe system. Different pipe diameters represent the amount of information passing through the pipe. In order to show the applicability of our approach, we conducted a case study in a globally distributed software engineering company. The study consists of the elicitation of information flows inside the company and the automated analysis by our approach. We are able to visualize the information flows, find critical paths such as bottlenecks, and improve information flow structures. This enables project leaders to customize the communication structure to the needs of their team and to prevent loss of information. Index Terms-Communication behavior, information sharing, development teams, developer network, social network analysis</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>I. INTRODUCTION</title>
      <p>
        Communication and information exchange are two essential
parts of daily work in software development teams [
        <xref ref-type="bibr" rid="ref1">1</xref>
        ]. An
inadequate amount of communication is one of the main
obstacles hampering successful collaboration [
        <xref ref-type="bibr" rid="ref2">2</xref>
        ], [
        <xref ref-type="bibr" rid="ref3">3</xref>
        ]. There
exist different types of information such as customer needs
or details of story cards that need to be shared within the
team [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ]. This intense communication takes place via different
communication channels, such as face-to-face, e-mails, chat
messages or documents [
        <xref ref-type="bibr" rid="ref4">4</xref>
        ], [
        <xref ref-type="bibr" rid="ref5">5</xref>
        ]. Developers and stakeholders
are often not aware of the ongoing communication behavior
and information flow [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ], [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ]. They frequently face the problem
of instantaneously accessing the right information due to
the distribution to different information stores. Information
flow is impeded if the developers do not know where to
find the required information. In turn, inadequate information
sharing complicates teamwork. Analyzing information flow
helps a team to become aware of the communication and
information sharing [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ]–[
        <xref ref-type="bibr" rid="ref10">10</xref>
        ]. Detecting critical issues helps
to improve the teamwork and to prevent problems like lost
information, missing functionality, and a dissatisfied customer.
There are different approaches to analyze the information flow
in projects [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ], [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ]. These approaches consider the existence
or absence of an information flow. However, they take neither
the amount nor the required time to transport information
from one person to another into account. Information can flow
directly between two persons, but it may also flow via different
persons before reaching the required team member.
      </p>
      <p>In this paper, we present the metaphor of a pipe system
to consider the wide range of ways to transport information –
and to facilitate the analysis of the information flow. The pipe’s
diameter resembles the amount of information transmitted per
time, e.g., via chat, phone, or face-to-face. Water in a pipe
system can take different ways from a source to a target, but
it is limited by the smallest pipe on the way. The same holds
for information: The maximum amount of information flowing
between two persons is limited by the minimum amount of
information that can be transported on each part on the way
from the sender to the receiver of information.</p>
      <p>
        We aim at visualizing a developer network with different
kinds of pipe diameters representing the amount of information
flow. The pipe system visualizes information flow within the
network and helps to detect critical paths and bottlenecks. This
facilitates the developers’ understanding of the importance of
adequate information sharing. Furthermore, central nodes can
be easily recognized in the network. These central nodes are
of particular importance for information sharing since they
bundle a lot of information [
        <xref ref-type="bibr" rid="ref13">13</xref>
        ].
      </p>
      <p>Despite the theoretical orientation of our paper, we apply
our approach in an industrial case study with a globally
distributed software developing company.</p>
      <p>The remainder of this paper is structured as followed:
In Sec. II, we present related work. In Sec. III, we depict
the groundwork of graph theory used in our approach and
the information flow analysis with FLOW. In Sec. IV, we
introduce our approach for an automated analysis of FLOW
diagrams based on pipe systems. Sec. V presents our case
study. The results and limitations of our approach are discussed
in Sec. VI. We conclude and present future work in Sec. VII.</p>
    </sec>
    <sec id="sec-2">
      <title>II. RELATED WORK</title>
      <p>
        Our work focuses on quantifying information flow analysis.
There are already existing approaches in this area. Durugbo et
al. [
        <xref ref-type="bibr" rid="ref14">14</xref>
        ] give an overview of existing approaches for modeling
information flow. The authors review literature and distinguish
between approaches for diagrammatically (i.e. visually) and
mathematically (i.e. analytically) modeling information flow.
According to the literature review of Durugbo et al. [
        <xref ref-type="bibr" rid="ref14">14</xref>
        ],
most visualizations are done using graphs or networks. Besides
graph theory and social network analysis, probability theory,
vector analysis, Markov models and interaction matrices are
also applied to analyze the information flows [
        <xref ref-type="bibr" rid="ref14">14</xref>
        ]. The choice
of visualization and analysis approaches often depends on the
level of application: It is possible to analyze information flows
on a macro, meso, and micro level [
        <xref ref-type="bibr" rid="ref15">15</xref>
        ]. Our concepts go along
with Durugbo et al.’s [
        <xref ref-type="bibr" rid="ref14">14</xref>
        ] findings which are not tailored for
software development teams.
      </p>
      <p>
        Smith [
        <xref ref-type="bibr" rid="ref16">16</xref>
        ] provides an overview of the foundations of
quantitative information flow. He mainly considers the flow of
secure information. His approach is based on the concept of
vulnerability, which is closely related to Bayes risk measuring
uncertainty [
        <xref ref-type="bibr" rid="ref16">16</xref>
        ]. The author focuses on sensitive information
as a security issue. His approach is not applicable to our
information flow analysis which is based on social interactions.
      </p>
      <p>
        Lowe [
        <xref ref-type="bibr" rid="ref17">17</xref>
        ] presents an approach of quantifying information
flow by considering the capacity of a covert channel in a
security system. His approach is based on the Communicating
Sequential Processes algebra describing interactions between
various kinds of communicating processes. Lowe [
        <xref ref-type="bibr" rid="ref17">17</xref>
        ]
considers an information flow between two users, High and Low,
using a covert channel. He wants to quantify the amount of
information flowing from High to Low. Lowe’s [
        <xref ref-type="bibr" rid="ref17">17</xref>
        ] approach
is more technical due to the use in security and not based on
human factors.
      </p>
      <p>
        Kiesling et al. [
        <xref ref-type="bibr" rid="ref13">13</xref>
        ] combine the FLOW method for
information flow analysis with social network analysis. They
apply various centrality measures which are well established
in sociology and psychology. These centrality measures
detect central persons who are very important for information
sharing. The authors consider degree centrality counting the
number of incoming and outgoing edges, closeness centrality,
betweenness and flow betweenness centrality. The different
measures indicate which persons are central from different
points of view or which are well situated in the network
to share and receive information very fast and easily. This
approach also helps to quantify information flow analysis
since certain centrality measures underline the qualitative
results. Compared to our approach, Kiesling et al. [
        <xref ref-type="bibr" rid="ref13">13</xref>
        ] only
consider whether there is an edge between two nodes, i.e. an
information exchange takes place. In contrast, we consider the
amount of information which flows over an edge.
      </p>
    </sec>
    <sec id="sec-3">
      <title>III. BACKGROUND Our approach of modeling information flow is based on graph theory and extends the FLOW method. In the following, we present the necessary basics to understand our approach.</title>
      <sec id="sec-3-1">
        <title>A. Graph Theory</title>
        <p>
          We use the Ford-Fulkerson-Method to realize our approach
of considering a developer network as pipe system [
          <xref ref-type="bibr" rid="ref18">18</xref>
          ]. We
consider a finite, directed graph G = (V; E) with a set of
nodes V and a set of edges E V V . This graph grasped
as a network is called flow network [
          <xref ref-type="bibr" rid="ref18">18</xref>
          ]. Let c : V V ! R 0
be a non-negative function assigning a capacity c(u; v) to each
edge (u; v) 2 E. This function is called capacity function. For
(u; v) 2= E, we assume that there is no information flow, i.e.
c(u; v) = 0. A flow in G is defined to be a real-valued function
f : V V ! R satisfying
1) Capacity constraint: 8u; v 2 V let f (u; v) c(u; v), i.e.
        </p>
        <p>the flow is always less or equal to the capacity
2) Skew symmetry: 8u; v 2 V let f (u; v) = f (v; u), i.e.</p>
        <p>going in the opposite direction leads to a negative flow
3) Flow conservation: 8u 2 V nfs; tg, let Pvu2V f (u; v) =
0, i.e. there is theoretically no loss of information in a
node; the amount of incoming information is equal to the
amount of outgoing information
Given a flow and a capacity function, we can define the
residual capacity, which is given by the difference between
the actual flow between to nodes and the capacity of the edge
connecting them. Formally, the residual capacity is defined to
be
cf (u; v) =
8&gt;c(u; v)
&lt;</p>
        <p>
          f (v; u)
&gt;:0
f (u; v) if (u; v) 2 E
if (v; u) 2 E
otherwise
Then, the residual network Gf = (V; Ef ) induced by a flow f
is given by the edges in Ef = f(u; v) 2 V V : cf (u; v) &gt; 0g.
Thus, the residual network consists of all nodes of the initial
network and the edges are given by those with a not yet
maximal flow. An augmenting path p is a simple path from s
to t in the residual network Gf . One may show that each edge
on such a path in the residual network admits some additional
positive flow from u to v without violating the capacity
constraint on the edge [
          <xref ref-type="bibr" rid="ref18">18</xref>
          ]. The residual capacity of an
augmenting path p is defined to be the maximum amount by which the
flow on each edge in p can be increased without violating the
capacity criteria, i.e. cf (p) = minfcf (u; v) : (u; v) is on pg.
        </p>
        <p>We aim at calculating the maximum information flow f (s; t)
between a source s 2 V and a target t 2 V . Therefore, we
apply the Ford-Fulkerson-Method. Algorithm 1 visualizes the
proceeding.</p>
        <p>Algorithm 1 FORD-FULKERSON-Method [18, p. 724]
1: for each edge (u; v) 2 G:E do
2: f (u; v) = 0
3: end for
4: while there exists a path p from s to t in the residual
network Gf do
5: cf (p) = minfcf (u; v) : (u; v) 2 pg
6: for each edge (u; v) 2 p do
7: if (u; v) 2 E then
8: f (u; v) = f (u; v) + cf (p)
9: else
10: f (v; u) = f (v; u) cf (p)
11: end if
12: end for
13: end while
In the beginning, the flow of each edge within the network
is initialized with zero. Then, we search for a path p from
the source s to the target t in Gf in the residual network Gf
induced by the current flow value. We calculate the minimum
of all residual capacities, cf (p) on p, and increase the flow of
each edge in E by this cf (p). If an edge is not contained in
the initial network, we decrease the contrary edge (v; u) by
the same value. This proceeding is well-defined and leads to
the requested results [18, p. 714 ff.].</p>
        <p>The Edmond-Karp-Algorithm implements the
FordFulkerson-Method with polynomial runtime. This algorithm
searches for the augmenting path (line 4 in Alg. 1) by using
breadth-first-search to find the shortest augmenting path from
s to t. This is helpful since the distance of the shortest path
from s to any other node v 6= t in the residual network
increases monotonically with each flow augmentation [18, p.
727]. Using this implementation decreases the runtime, since
the total number of flow augmentations is in O(V E) [18, p.
729]. The total runtime is O(V E2).</p>
      </sec>
      <sec id="sec-3-2">
        <title>B. Information flow analysis with FLOW</title>
        <p>
          FLOW is an established method to analyze and improve
the communication in software projects [
          <xref ref-type="bibr" rid="ref12">12</xref>
          ]. It is a
systematic analysis of information flows in software development
projects, but it is also applicable for other kinds of projects.
FLOW helps to detect lacks or anomalies in order to avoid a
loss of information by providing a structured proceeding for
evaluating, visualizing, analyzing and improving information
flow in teams [
          <xref ref-type="bibr" rid="ref12">12</xref>
          ], [
          <xref ref-type="bibr" rid="ref19">19</xref>
          ].
        </p>
        <p>
          FLOW distinguishes between two types of information
flows and stores: solid and fluid [
          <xref ref-type="bibr" rid="ref19">19</xref>
          ]. Solid information is
long-term and repeatably accessible and can be understood
by third parties with domain knowledge. An information flow
is defined to be fluid, whenever one of these three criteria is
not met [
          <xref ref-type="bibr" rid="ref12">12</xref>
          ]. Solid information is usually captured in
written documents, source code or other long-living stores [
          <xref ref-type="bibr" rid="ref12">12</xref>
          ].
Examples for fluid information are undocumented meetings,
informal face-to-face communication and implicit knowledge
[
          <xref ref-type="bibr" rid="ref10">10</xref>
          ]. Emails may be either fluid or solid, depending on the
further use and storing of the email [
          <xref ref-type="bibr" rid="ref10">10</xref>
          ].
        </p>
        <p>
          Analysts conduct interviews with important members of
the project to elicit the communication behavior. The group
of interviewed persons often consists of the team leader,
one or two developers and other important stakeholder or
contributor to the team’s work. Each interview starts with a
short introduction of the interviewee to give an overview of the
main tasks. For each task, the interviewee names the involved
persons and the required information (input), the working
products (output), the supporting artifacts such as templates,
standards or tools [
          <xref ref-type="bibr" rid="ref13">13</xref>
          ].
        </p>
        <p>The results of the FLOW interviews are visualized in a
FLOW diagram. Figure 1 presents the main information stores
(faces for fluid stores and documents for solid stores). The
rectangle represents an activity summarizing parts of the
diagram that are too fine-grained for the visualization or that are
not further defined during the interviews. Note that the FLOW
diagram is a directed network since information mainly flows
from one person to another, even if the interaction (mostly
communication) is usually bidirectional. If an information flow
is bidirectional, i.e. information flows from A to B as well as
from B to A, this is visualized by an arrow pointing in both
directions.
Figure 1 visualizes the activity Sprint Planning with incoming
information from the Scrum Master, the Product Owner, the
Scrum Team and the Backlog, which is usually documented on
a task board or in a ticket system and hence solid. The result of
the task are Story Cards for the next Sprint. The Template for
Story Cards controls the task and Trello1 supports the activity.</p>
        <p>
          FLOW diagrams mostly comprise various patterns. During
the analysis, these patterns need to be found in order to
detect weaknesses. For example, a long chain of fluid
information stores (also referred to as Chinese-whisper-pattern) [
          <xref ref-type="bibr" rid="ref21">21</xref>
          ]
should be avoided since the information may change during
the transfer due to misunderstandings. Another example for a
pattern is the Competence Spider [
          <xref ref-type="bibr" rid="ref22">22</xref>
          ]. This is a person that
receives and shares a lot of information. An absence of such
a person endangers the information flow.
        </p>
        <p>Afterwards, the analyst presents his findings and discusses
possible improvements with the project team. He further
suggests how the team can use its resources more appropriately.</p>
      </sec>
    </sec>
    <sec id="sec-4">
      <title>IV. QUANTIFYING INFORMATION FLOW</title>
      <p>In order to support the FLOW analyst during the analysis
as well as to allow project leaders and team members to
analyze the FLOW diagram, we want to support the analysis
with quantitative measures and visualizations. In order to
implement our metaphor of a pipe system, we have to make
some assumptions which we present in this section.</p>
      <sec id="sec-4-1">
        <title>A. Weighting Information Flow</title>
        <p>
          In a first step, we define the diameter of the pipes which are
given by weights for the edges. The weights represent the
amount of information flowing between two nodes [
          <xref ref-type="bibr" rid="ref23">23</xref>
          ]. A
small weight defines a small flow capacity whereas a large
weight defines a large flow capacity.
        </p>
        <p>Considering a FLOW diagram, we have to distinguish
between four cases without activities and four cases with
1https://trello.com/
activities: Each combination of fluid and solid stores (solid
! solid, solid ! fluid, fluid ! solid, fluid ! fluid) and
combinations with an activity (fluid ! activity, solid !
activity, activity ! fluid, activity ! solid). We define the
amount of information flow between two information stores
according to their states as represented in Table I. We define
the edge weights representing the amount of information
flow between two nodes to range between 0 and 1, where
0 represents no information exchange.
The weights in Table I require some assumptions:
fluid ! fluid: Transporting information directly and
personally enables a good flow of information because the
receiver is able to directly ask questions in order to
understand what the source tells him.
fluid ! solid: Information sharing from a fluid store to
a solid one like writing something down, is worse than
information sharing between persons, since the source
cannot write everything down or may forget implicit
knowledge. Hence, the receiver has less information than
the source.
solid ! fluid: Reading is one example for
transforming information from a solid store to a fluid one. The
amount of information received by reading the document
strongly depends on the receiver’s knowledge. Missing or
not understandable information may not be retrieved by
reading the document twice. The only way of receiving
missing specific information is talking to the source of
the document.
solid ! solid: Information sharing from a solid store
to another solid store is given by copying documents
or changing the file format. However, since there is no
human involved in the process, we assume a very low
“collaboration” between these documents.</p>
        <p>These assumptions imply the decreasing weights in Table I. In
the case of information flows with involved activities, we have
to make different assumptions. We know either the source or
the receiver, but one of them is an activity, which is, first of
all, a black box. Hence, we do not know the granularity of
the information flow, i.e. if it is solid or fluid. Sometimes,
knowledge about the activity helps to decide whether an
information flow is solid or fluid, but in many cases, this
decision is not possible.</p>
        <p>
          We consider information flows within activities as the worst
case and choose the minimum edge weight which is given
by the information flow between two solid stores, i.e. 0.2, in
case of doubts. We assume that information flows during each
activity, since according to Watzlawick et al. “one cannot not
communicate” [
          <xref ref-type="bibr" rid="ref24">24</xref>
          ]. However, it is also possible to reduce the
activities as described in the following.
        </p>
      </sec>
      <sec id="sec-4-2">
        <title>B. FLOW Diagrams as Pipe Systems</title>
        <p>
          We aim at applying the Edmond-Karp-Algorithm of the
FordFulkerson-Method for calculating the maximum flow within
a network to the FLOW diagram. In order to apply this
algorithm, we first have to adjust the FLOW diagram, since
the algorithm only considers nodes and edges, but no activities
as in FLOW. As presented by Kiesling et al. [
          <xref ref-type="bibr" rid="ref13">13</xref>
          ], there are
mainly three possibilities of transforming a FLOW diagram
into a network:
1) Connect all incoming and outgoing stores of the activity.
2) Represent the activity with a separate node and connect
all incoming and outgoing nodes with this one by
preserving the direction of flow.
3) Decide for each incoming node whether it should be
directly connected to an outgoing one or to a separately
defined one. This case requires deeper insights into the
activity.
        </p>
        <p>There are some prerequisites deciding which case is most
suitable.</p>
        <p>Case 1 implies that there is an information flow from
each incoming to each outgoing node involved in the
activity. For example, in case of a meeting, this might
be correct. However, activities often represent a further
communication network where the information does not
necessarily flow from each incoming to each outgoing
node.</p>
        <p>Case 2 is the most neutral way of integrating an activity
within a network. After having analyzed the network, it
might be possible to re-transfer the network into a FLOW
diagram and adapt the results for analyzing the diagram.
In case of doubts, we recommend using this possibility.
Case 3 is the most exact way of dissolving an activity.
This case requires deep insights into the activity that
cannot always be achieved.</p>
        <p>Depending on the choice of the case, there are different
interpretations of the resulting network. In order to connect
both approaches, i.e. the FLOW analysis and the algorithmic
extension, it is required not to change the core statements of
the network. Hence, the transformation method needs to be
carefully selected for each activity.</p>
        <p>After this step, we receive a FLOW network only consisting
of information stores and information flows, i.e. nodes and
edges. We are now able to apply the algorithm to the network.</p>
      </sec>
      <sec id="sec-4-3">
        <title>C. Quantitative Measures</title>
        <p>
          Based on the pipe system and the use of the
Edmond-KarpAlgorithm, we calculate the maximum flow between two
nodes. Comparing the results between different nodes and
considering the paths of the maximum flow helps to detect
central persons, i.e. persons who are very important for the
information flow. A person can be central from different
viewpoints. Social network analysis is a wide field providing
different measures for centrality [
          <xref ref-type="bibr" rid="ref23">23</xref>
          ]. Kiesling et al. [
          <xref ref-type="bibr" rid="ref13">13</xref>
          ] apply
commonly used centrality measures to the nodes of a FLOW
diagram. Table II summarizes some centrality measures and
explains their relevance for information flow analysis. All
of these centrality measures are local ones, i.e. they can be
calculated for a single node.
        </p>
        <p>
          These measures help to detect critical issues in the network
[
          <xref ref-type="bibr" rid="ref13">13</xref>
          ]. Some of them are obvious in the FLOW diagram, e.g.
the degree centrality. One only needs to count the incoming
and outgoing edges of a node and the nodes that have a lot of
them are central in the sense of degree centrality. The persons
represented by the nodes seem to have a certain importance
for the information flow process. However, other measures
such as the closeness centrality are difficult to identify in a
network without having calculated the measures. We provide
a visualization for the closeness centrality which measures the
average distance of a node to all other nodes in the network
in order to facilitate understanding of persons who are central
in the sense of closeness centrality. We call this visualization
network expansion since we highlight all nodes that can be
reached by a certain node after 1, 2, 3, or more steps. The
more nodes a node can reach within a few steps, the higher
the closeness centrality. It remains future work to provide
visualizations for the other centrality measures that are not
easy to determine.
        </p>
      </sec>
      <sec id="sec-4-4">
        <title>D. Analyzing the resulting network</title>
        <p>We implemented a prototype depicting the transformed FLOW
diagram and then calculating the maximum information flow
from a source to a target. Figure 4 represents a screenshot of
the tool. All fluid information stores are visualized as circles
and all solid stores are rectangles. Currently, activities are
represented as squares but have the same properties as the
other nodes. The distinction between the information stores
only supports the intuitive comprehension of the network; the
algorithm does not differ between the type of information
because this information is already contained in the pipe
diameter. In Figure 4, the purple node in the upper left corner
is the source and the orange node in the lower right-hand
corner is the target, i.e. the receiver of the node. The blue path
visualizes the best ways for information sharing according to
the Edmond-Karp-Algorithm.</p>
        <p>The tool also includes the visualization of the network
expansion (see Figure 3) and the calculation of the centrality
measures in Table II. To facilitate the interpretation of the
centrality measures, our tool is able to highlight the extreme
values, i.e. those differing from the other ones.</p>
      </sec>
    </sec>
    <sec id="sec-5">
      <title>V. CASE STUDY IN INDUSTRY We present a preliminary study with a globally distributed software engineering company [22] to demonstrate the applicability of our approach.</title>
      <sec id="sec-5-1">
        <title>A. FLOW Analysis</title>
        <p>According to the proceeding presented in Sec. III-B, we have
interviewed the director of the company. In this interview,
we gained profound knowledge about the information sharing
behavior. The FLOW diagram after the first interview is rather
small and clear. In order to present the proceeding of our
quantitative analysis, it is sufficient and better to use a rather
small, but clear FLOW diagram.</p>
        <p>In the first interview, we collected data about the overall
corporate structure, the hierarchies and the communication
behavior within and across the teams. We talked to the director
who has a good overview of all processes. The whole interview
took about two hours. It started with some demographics about
the director, his experiences and his background. Afterwards,
he started describing the overall process. We took notes on
the main activities and asked him about the results, incoming
information, supporting tools and persons, and controlling
elements such as templates. In the end, we summarized the
results of the interview, i.e. the information on the main
activities during the process to avoid misunderstandings.</p>
        <p>
          We visualized the findings based on the interviews as a
FLOW diagram. The result of the interview is presented
in Figure 2 [
          <xref ref-type="bibr" rid="ref22">22</xref>
          ]. The developers work in Spain, while the
customer and the consultants are in Germany. To coordinate
the communication across borders, each team has a team
leader who exchanges information with the other team leader.
A project starts with a workshop (see (1) in Figure 2). The
director, the customer and both team leader participate in the
workshop. It helps to clarify basic conditions. The workshop
results in a requirements catalog (2) documenting all
requirements. Based on this requirements catalog, the consultants
write story cards for the developers in Spain and create a
concept. A click-dummy (3) basically visualizes the idea for
the final product. The developers implement the story cards
and regularly exchange information with the consultants (4)
in Germany, who are in contact with the customer. In the end,
the customer receives the remaining software product to test
it and to express change requests. This step is not visualized
in Figure 2.
        </p>
      </sec>
      <sec id="sec-5-2">
        <title>B. Tool-Supported Analysis</title>
        <p>We consider exemplary the information flow from the team
lead (purple node) to the developers (orange node) in Figure 4.
The workshop, the requirements catalog and the click-dummy
lay on the path of the maximum flow from the team lead to
the developers. The most important node are the consultants
because they lay on each of the paths. If this node is missing,
information would flow worse or even not at all from the
team leader of the consultants to the developers. The centrality
measures of this node (closeness: 0.08, betweenness: 0.84,
in-degree: 7, out-degree: 12) also support this fact. All of
them are highlighted, i.e. they differ remarkably from the
measures of all other nodes. The workshop (betweenness: 0.60,
in-degree: 6, out-degree: 2) and the developers (betweenness:
0.49, in-degree: 4, out-degree: 4) are also very important.</p>
        <p>Considering the information expansion of the consultants
(central node) and the quality assurance (decentral node) in
Figure 3 illustrates the benefit of this measure. Figure 3a
visualizes the information expansion of the consultants that
only need 2 steps to cover the whole network. Figure 3b
presents the information expansion of the quality assurance
which is rather decentral. This node needs 4 steps to cover
the whole network. The main reason for this finding is that
the quality assurance only talks directly to the developer which
can also be found in the network.</p>
      </sec>
    </sec>
    <sec id="sec-6">
      <title>VI. DISCUSSION In the following, we reflect on the limitations of our approach before interpreting and discussing our findings from the example above.</title>
      <sec id="sec-6-1">
        <title>A. Critical Appraisal</title>
        <p>Due to the basically conceptional approach in this paper, the
presented idea has two deficiencies, which are not unimportant
for the interpretation and the reliability of the results after the
application of our approach: (1) the choice of the algorithm
and (2) the weightings of the information flow.</p>
        <p>(1) The choice of the algorithm: There exist many different
algorithms for calculating the maximum flow in a network.</p>
        <p>Hence, there might be a better algorithm for our approach.</p>
        <p>
          We decided to use the Ford-Fulkerson-method which is widely
distributed in graph theory and which is even recommended by
Cormen [
          <xref ref-type="bibr" rid="ref18">18</xref>
          ] for considering information flows in a network.
        </p>
        <p>
          (2) The weightings of the information flows: The proposed
weightings in Table I underly some assumptions presented in
subsection IV-A. For calculations, we had to postulate concrete
values. Although the assigned values seem arbitrary, they are
chosen carefully based on the assumptions presented in
subsection IV-A. But slightly different values with a comparable
scaling do not lead to completely different results. The range
from 0 to 1 is based on the calculation of FLOW distance,
which defines the amount of information flow in smaller teams
and also ranges from 0 to 1 [
          <xref ref-type="bibr" rid="ref4">4</xref>
          ]. Nonetheless, the values
represent the current state of our research and may need to
be adjusted later due to new findings. However, the basic idea
remains valid also with slight adjustments. Nonetheless, we
do not consider human factors influencing the information
flow such as a node’s absorption of information. The ability
of a person to absorb and internally handle information can
increase or decrease the amount of information to be shared
(a) Information expansion of a central node
(b) Information expansion of a decentral node
Figure 3: Stepwise information expansion. The colour of the starting node is red, turning towards blue with each additional
step. Furthermore, the diameter of the coloured circle around the node decreases.
with other persons. Furthermore, we do neither consider the
loss of information nor misunderstood information that are
falsely shared. We will consider these aspects, in particular
”personalized” weightings, in further research.
        </p>
      </sec>
      <sec id="sec-6-2">
        <title>B. Interpretation</title>
        <p>Information flow in software development teams or companies
is a very complex behavior which requires a manual analysis.
Some structures or patterns in the FLOW diagram are too
interwoven and subliminal to be detected by a simple algorithm.</p>
        <p>We want to support the information flow analysis and
increase the developers’ awareness of the complexity of
information sharing by presenting an approach of metaphorically
considering a developer network as a pipe system. Hence, we
quantify information flow analysis to apply the algorithm. This
helps to increase the trustworthiness of the findings due to
underlying data. Furthermore, it decreases the possibility of
missing interpretations and forgotten obvious things. It helps
to make the subjective analysis more objective.</p>
        <p>Our case study reflects the advantages of the interplay of
both qualitative and quantitative information flow analysis. The
qualitative method finds complicated structures and patterns
such as the “Chinese-whisper-pattern”. The quantitative
analysis detects the same issues and – after adaptions and extensions
– it may help to increase the developers’ awareness for the
current state of information flow by visualizing and simulating
the results. It currently detects ways of information flow that
are too long to be suitable or that are duplicated. However,
the analysis needs to be sharpened and extended to gain real
benefits from the quantifications.</p>
        <p>In the given example, we figured out the importance of the
consultants within the process. A FLOW analyst recognizes
the consultants as so-called ”competence spider” because they
are involved in many information flows. As evident from the
FLOW diagram, there are many incoming and outgoing edges
from and to the consultants. Our pipe system supports the
relevance of the consultants. The underlying data confirm that
the consultants are at least mandatory for a fast information
flow from the team leader to the developers. Without the
consultants managing and coordinating the information sharing,
an information flow from the team leader to the developers
cannot be guaranteed. Furthermore, the centrality measures
and the information expansion underline the importance of
the consultants objectively. This objectivity may also help to
increase the awareness of the involved persons. A qualitative
analysis is always subjective, but the calculated measures
are objective and the results easier to comprehend. However,
there is some analysis required to support this assumption.
The qualitative and the quantitative method supplement each
other. Nonetheless, the quantitative method needs to be refined
and extended to increase the advantages and to evaluate the
practicability.</p>
      </sec>
    </sec>
    <sec id="sec-7">
      <title>VII. CONCLUSION AND FUTURE WORK</title>
      <p>Information exchange is important in software development
teams. Furthermore, information needs to be shared between
the customer, the team, project leader and many other different
involved persons.</p>
      <p>One strategy to analyze information flow is the FLOW
method which aims at observing, examining, and improving
information flow in teams and companies. Until now, the
FLOW method is a basically subjective method and the results
depend on the analyst’s experience and knowledge.</p>
      <p>In this paper, we presented the conceptional idea of
metaphorically considering the developer network as a pipe system.
We defined the amount of information flow between two nodes
in the network based on the states of information flow provided
by FLOW. Information flow can then be analyzed based
on established algorithms in graph theory. In this approach,
we use the Ford-Fulkerson-method which is widely used to
calculate the maximum flow in a flow network.</p>
      <p>
        We applied our approach to a software development
company which results after the first interview have already been
analyzed corresponding to the FLOW method [
        <xref ref-type="bibr" rid="ref22">22</xref>
        ]. We were
able to detect some findings which are rather obvious (e.g.
the important role of the consultants) and have also been
retrieved in the qualitative analysis. However, we can objectively
support these findings by presenting centrality measures.
      </p>
      <p>In future, we will evaluate the influence of our approach
on the developers, i.e. if our approach increases the awareness
for the relevance of information sharing. Furthermore, we plan
to graphically simulate information flow in the network and
include further metrics to measure the quality of information
flow. Additionally, our automated approach with pipe systems
is still based on a manual elicitation phase of the
information flows. This phase consists of interviews with project
members and drawing a flow diagram. This is highly
timeconsuming and requires an experienced analyst. In order to
enable software companies to conduct a flow analysis on their
own without any expertise, we have to automate the elicitation
phase of the flow analysis as well. At the moment, we deal
with this problem in future and ongoing research.</p>
    </sec>
    <sec id="sec-8">
      <title>ACKNOWLEDGMENT</title>
      <p>This work was supported by the German Research Foundation
(DFG) under grant number 263807701 (project
TeamDynamics, 2018-2020).</p>
    </sec>
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