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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Understanding strategic moves and reciprocity on Software Ecosystems: A strategic modeling approach</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Vik Pant</string-name>
          <email>vik.pant@mail.utoronto.ca</email>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Eric Yu</string-name>
          <email>eric.yu@utoronto.ca</email>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff1">1</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Department of Computer Science, University of Toronto</institution>
          ,
          <addr-line>Toronto</addr-line>
          ,
          <country country="CA">Canada</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Faculty of Information, University of Toronto</institution>
          ,
          <addr-line>Toronto</addr-line>
          ,
          <country country="CA">Canada</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2017</year>
      </pub-date>
      <fpage>28</fpage>
      <lpage>42</lpage>
      <abstract>
        <p>Many software ecosystems comprise rival vendors that cooperate and compete with each other simultaneously. This type of relationship is termed coopetition wherein enterprises cooperate to increase collective benefits while competing to maximize their individual gains. In such a relationship, strategic moves by an actor can have significant consequences for other actors in the ecosystem. This paper proposes a model-based approach for analyzing strategic moves in software ecosystems using i* and game trees. We offer a methodology for developing complementary i* models and game trees. We also explicate guidelines for applying this methodology in a consistent manner. We draw upon a published case study as an illustrative example and instantiate a model based on it to assess the strengths and weaknesses of this methodology.</p>
      </abstract>
      <kwd-group>
        <kwd>Software Ecosystems</kwd>
        <kwd>Coopetition</kwd>
        <kwd>Reciprocity</kwd>
        <kwd>Analysis</kwd>
        <kwd>Game Tree</kwd>
        <kwd>Business Modeling</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>Introduction</title>
      <p>Modeling can help decision-makers by supporting the representation and reasoning
of coopetitive strategies within SECOs in a structured and systematic manner.
Modeling can be used to evaluate the advantages and disadvantages as well as tradeoffs of
various strategic alternatives available to participants in SECOs. Moreover, it can be
used by SECO participants to compare known alternatives for coopeting as well as to
generate new alternatives.</p>
      <p>
        Management researchers have identified key characteristics of coopetition [
        <xref ref-type="bibr" rid="ref10 ref11 ref12 ref13 ref14 ref15 ref16 ref17 ref9">9-17</xref>
        ].
These include reciprocity [
        <xref ref-type="bibr" rid="ref14">14</xref>
        ], complementarity [
        <xref ref-type="bibr" rid="ref15">15</xref>
        ], interdependence [
        <xref ref-type="bibr" rid="ref16">16</xref>
        ], and
trustworthiness [
        <xref ref-type="bibr" rid="ref17">17</xref>
        ]. Reciprocity refers to tit-for-tat (TFT) behavior in which an actor
responds to a move by another actor, that it perceives to be cooperative or competitive,
in a symmetrical manner. Sundali and Seale [
        <xref ref-type="bibr" rid="ref18">18</xref>
        ] note that reciprocity is a useful
predictor of countermoves within coopetitive relationships.
      </p>
      <p>
        Cygler and Sroka [
        <xref ref-type="bibr" rid="ref19">19</xref>
        ] assert that reciprocity increases the welfare in a relationship
because cooperative actions by an actor are rewarded by cooperative actions of other
actors in return. However, Ma [
        <xref ref-type="bibr" rid="ref20">20</xref>
        ] notes TFT is not an ideal strategy in all situations
because under certain circumstances forbearance yields more favorable outcomes than
retaliation. Therefore, in coopetitive relationships, it is important for decision-makers
to understand when and why restraint is preferable to revenge.
      </p>
      <p>The scenarios of multi-listing and multi-homing on SECOs illustrates reciprocity in
action. The manager of a SECO (e.g., operator or provider) may allow competing
offerings from rival software vendors (i.e., app developer) to be listed in its catalog (i.e.,
multi-listing). In response, an app developer may list its offerings in catalogs on
multiple competing platforms (i.e., multi-homing). Alternatively, a SECO manager may
allow privileged access to a section of its catalog to a specific app developer so that only
that app developer can offer its apps in that category. In response, that app developer
may decide to offer its apps exclusively on that SECO catalog.</p>
      <p>In this paper, we propose a complementary approach for modeling reciprocity using
i* and game trees in a synergistic manner. Game trees elide the intentional structure of
the players while i* omits the notion of time and sequence. However, by using game
trees and i* together we overcome the individual limitations of each approach. We
argue that i* and game trees provide a stronger basis for analyzing decisions, about
strategic moves and reciprocation, together rather than separately.</p>
      <p>We discuss the need for modeling reciprocity in coopetitive relationships. We also
elaborate on the concepts of strategic moves and reciprocity in coopetition. In the third
section, we propose an approach for modeling strategic moves and reciprocity using i*
and game trees. In the fourth section, we draw upon a published case study as an
illustrative example and instantiate a model of strategic moves and reciprocity based on it.
In the fifth section, we discuss related work on modeling of SECOs. In the sixth and
seventh sections, we discuss key findings from this line of research and outline future
work.</p>
      <p>
        Strategic Moves and Reciprocity in Coopetition
In the literature on coopetition, reciprocity refers to "rewarding kindness with kindness
and punishing unkindness with unkindness" [
        <xref ref-type="bibr" rid="ref21">21</xref>
        ]. It facilitates cooperation among
actors by serving as a guarantor of favorable treatment and a protector against injurious
behavior. It "is a rather stable behavioral response by a nonnegligible fraction of the
people" [
        <xref ref-type="bibr" rid="ref22">22</xref>
        ] and thus each social actor should "expect this behavior from others" [
        <xref ref-type="bibr" rid="ref23">23</xref>
        ].
      </p>
      <p>
        Strategic reciprocity has been observed in many industrial settings [
        <xref ref-type="bibr" rid="ref24">24</xref>
        ]. However,
despite its ubiquity and enduring nature as an influencer of social behavior, there are
circumstances in which reciprocity can yield counter-productive decisions that lead to
detrimental courses of action. Therefore, decision-makers within organizations can
benefit by analyzing reciprocity using a systematic and structured approach. For
instance, a decision-maker might need to evaluate whether a strategic move will lead to
a mutually beneficial or unilaterally advantageous outcome for stakeholders.
      </p>
      <p>
        Reciprocity drives actor behavior in many intra- and inter-organizational [
        <xref ref-type="bibr" rid="ref25">25</xref>
        ] as well
as inter-personal [
        <xref ref-type="bibr" rid="ref26">26</xref>
        ] relationships. It serves as a guideline for action whereby one actor
is assured that its beneficial/deleterious actions towards other actors will be met by a
symmetrical response from those other actors. Reciprocity also impacts trust between
actors because it incorporates mutuality into a relationship such that good behavior by
an actor is rewarded with an increase in trust while bad behavior is punished with a
decrease in trust [
        <xref ref-type="bibr" rid="ref27">27</xref>
        ]. Reciprocity can be justified in any relationship because it
signifies the universal qualities of balance (symmetry) and fairness (equality).
      </p>
      <p>
        Reciprocity has been studied extensively by researchers of economics, sociology,
and psychology to explain moves and countermoves of actors in many types of social
relationships. In game theory, it is a basic assumption in many sequential move games,
such as gift-exchange game and ultimatum game [
        <xref ref-type="bibr" rid="ref28">28</xref>
        ]. For example, in the multi-listing
scenario, if a manager decides to allow rival app developers to offer their apps in its
catalog then some of those app developers may defect from that platform and switch to
other ecosystems. Conversely, in the multi-homing scenario, if an app developer
decides to offer its apps in catalogs on competing SECOs then a manager of one of those
SECOs may exclude that app developer from its ecosystem.
      </p>
      <p>This can lead to a series of reprisals that destabilize and undermine the relationship
between managers and app developers on SECOs to their collective detriment.
Conversely, a SECO manager or app developer may forego their impulse for short-term
TFT by thoroughly evaluating the longer-term implications of reciprocal reactions.
Therefore, a decision-maker might need to assess whether a reflexively reciprocal
reaction will merely satisfy its short-term cravings or fulfill its longer-term strategic
objectives.</p>
      <p>The universality and timelessness of reciprocity, as a motivator of actions/reactions
in strategic relationships, necessitate an approach for analyzing it in a detailed and
deliberate manner. Such an approach can enable a decision-maker to take history into
account and make tradeoffs between long and short-term interests. A decision-maker
might need to use such an approach to reason about behaviors that entail one actor
retaliating to the most recent move by another actor by taking the most self-interested
immediate action, thus potentially foregoing longer-term strategic interests.</p>
      <p>
        Case Study: Adobe Flash &amp; Apple iOS App Store Ecosystem
The business relationship between Apple and Adobe is instructive for illustrating the
impact of strategic moves and reciprocity on SECOs. Apple and Adobe were rivals
because each intended to establish market superiority of its ecosystem and technology
platform [
        <xref ref-type="bibr" rid="ref35">35</xref>
        ][
        <xref ref-type="bibr" rid="ref36">36</xref>
        ]. Figure 1a depicts the intentional structures of Apple and Adobe as
well as their dependencies on each other via an actor-model. Figure 1b represents a
game tree showing the interrelated decision spaces of these actors.
      </p>
      <p>
        A game tree offers an approach for decision analysis when the decisions of one actor
impact the decisions of other actors and vice versa. Game trees are variations of
decision trees in that, while decision trees depict the decisions of a single actor, game trees
portray the decisions of multiple actors [
        <xref ref-type="bibr" rid="ref29">29</xref>
        ]. They are relevant for modeling reciprocity
in coopetition because the decisions of an actor can trigger TFT countermoves by other
actors.
      </p>
      <p>
        Ziegler [
        <xref ref-type="bibr" rid="ref30">30</xref>
        ] notes that "a game tree is a graphical representation of the players'
possible choices (also called their action sets) at each point in time, the sequence in which
these choices are made, and the payoffs resulting from any combination of choices." It
supports the depiction of decisions, their sequence in terms of precedence and
subsequence, as well as the payoffs associated with each decision path from root to leaf
nodes. Borovska and Lazarova [
        <xref ref-type="bibr" rid="ref31">31</xref>
        ] point out that game trees can be used to “find the
optimal strategy as a sequence of best possible moves of a given player taking into
account possible moves of the other player up to a given depth.”
      </p>
      <p>Since decisions, their sequence, and payoffs are included in game trees they can be
used to solve optimization problems by searching the space of alternatives and
outcomes. However, for an actor to develop a game tree it is necessary for that actor to
understand the intentional structures of other actors that are included in that game tree.
This is required for approximating the payoffs for those actors from various decision
paths. Each actor may evaluate a decision path differently based on its preferences and
priorities. Therefore, any actor that wishes to reason about the perceived payoffs for
other actors must recognize the unique propensities and proclivities of each of those
actors.</p>
      <p>We posit that game trees and actor modeling with i* can be used together to achieve
a deeper understanding of the decision space as well as to secure a stronger decision
rationale. This is because while game trees support the depiction of payoffs they do not
explicitly codify the reasons for those payoffs. While payoffs are calculated values that
are based on the intentions and motivations of actors these features are only indirectly
reflected within those payoffs.</p>
      <p>
        However, even though the internal intentional structure of an actor cannot be
expressed directly in game trees it can be represented via i* Strategic Rationale (SR)
diagrams. i* is a socio-technical modeling language that is useful for analyzing intentional
relationships between actors [
        <xref ref-type="bibr" rid="ref32">32</xref>
        ]. Its key elements are actors, goals, tasks, softgoals,
and resources while its main links are for representing means-ends, decomposition,
contribution, and dependency relationships. A detailed summary of i* is offered in [
        <xref ref-type="bibr" rid="ref33">33</xref>
        ].
Apple
iOS be adopted in smart
mobiledevice market
Allow Objective-C
codeonly
      </p>
      <p>IDE be
required
Mandate
XCode only</p>
      <p>α: ß:
Revenue from !!
apps be
centralized</p>
      <p>α: ß:
Security of apps !!
becontrol ed</p>
      <p>Allow comingled
Objective-C and</p>
      <p>Flash code</p>
      <p>Support
Thirdparty IDEs</p>
      <p>α: ß:
innEoxvtaetrinoanlbe !
encouraged
α: ß:
App developers !
beattracted</p>
      <p>α: ß:
Translation be
permitted</p>
      <p>α: ß:
Mobile apps be
supplied
α: ß:
API be
accessible α: ß:</p>
      <p>Platform be
legitimated
Adobe</p>
      <p>Apple
Apple</p>
      <p>Apple operated an App Store that contained a catalog of apps that were compatible
with iOS devices (iPod, iPhone, and iPad). These apps were developed using a
proprietary Apple programming language (Objective C) on an integrated development
environment (XCode). Apple dictated strict terms and conditions for developing apps and
for listing those apps on its ecosystem. For example, Apple stipulated that apps could
only conduct monetary transactions with users via its Apple payment gateway.
Candidate apps by third parties were also screened by Apple for compliance with its rules.</p>
      <p>Adobe Flash was already widely adopted on the public Internet as a multimedia
technology for webpages. Adobe operated its own ecosystem (Flash Gallery) that
comprised of Flash-based apps. Flash was supported by many desktop web browsers via
plug-ins and Adobe’s intention was to bring Flash-based apps to touchscreens on
mobile devices (e.g., on Apple iOS, Google Android, etc.). Third-party app developers
welcomed the opportunity for expanding the reach of their existing Flash-based apps
for desktop web browsers onto mobile devices such as smartphones and tablets.</p>
      <p>
        In i*, an actor is an entity that is characterized by its intentionality, autonomy,
sociality, abstract/physical identity, contingent boundary, strategic reflectivity, and pursuit
of rational self-interest [
        <xref ref-type="bibr" rid="ref34">34</xref>
        ]. In figure 1a, Apple and Adobe are depicted as actors. A
goal is a state of affairs in the world that an actor wishes to achieve. In figure 1a, Apple
has a goal titled “iOS be adopted in smart mobile device market” while Adobe has a
goal “Flash be adopted on smart mobile devices”.
      </p>
      <p>A task is an alternative means for achieving an end. For example, Adobe can make
Flash compatible with iOS devices by “Referencing Objective-C API” or by
“Translating Flash code to Objective-C code in its own IDE”. A softgoal is a quality objective
that is considered to be satisfied or denied only from the perspective of an actor. In
figure 1a, Apple has various soft-goals with one titled “Revenue from apps be
centralized” and another titled “Security of apps be controlled”.</p>
      <p>A resource is an informational or physical entity that is necessary for fulfilling a
task. i* also supports the depiction of the relative priority of an element for an actor.
For example, Adobe treats “Existing Flash apps be supported” as a more important
softgoal with a “!!” priority than “Apps be optimized for iOS”, which is a softgoal with
a relatively lower priority of a “!”.</p>
      <p>Various aspects of i* make it suitable for analyzing strategic moves including its
support for means-ends reasoning, dependency link evaluation, contribution analysis,
label propagation, and task-decomposition. A means-end link shows the relationship
between a goal and the tasks that serve as alternatives for achieving that goal. A
dependency link connects an actor that depends (i.e., depender) to another actor on which
the depender depends (i.e., dependee) for something (i.e., dependum). A contribution
link shows the impact (e.g., help, hurt) of alternatives on softgoals.</p>
      <p>The cascading effect of a lower level element on higher level elements that are
impacted directly or indirectly is shown via label propagation. This allows bottom up
analysis to be conducted wherein the effect of an operationalizing element can be traced
upwards to strategic elements. A decomposition link shows the relationship between a
task and its constituent parts such as sub-goals, sub-tasks, sub-softgoals, and resources.
The completion of any task leads to the attainment of its corresponding goal. Each of
the components of a task need to be completed for that task to be accomplished.</p>
      <p>Adobe was the first-mover in this case, and is shown as the first decision-maker in
figure 1b, since it decided to support Flash-based apps on Apple iOS devices. Adobe
faced an important question regarding which of the two existing options was preferable
for bringing Flash-based apps to Apple iOS devices? As shown in figure 1a, there were
two main approaches for making Flash-based apps compatible with iOS devices. These
approaches are represented as alternate means for achieving an end.</p>
      <p>In one approach Flash code could be made interoperable with native iOS application
programming interfaces (APIs) (i.e., comingling option). In a different approach, an
Adobe IDE for Flash could serve as a translation tool to convert Flash code to
Objective-C code (i.e., translation option). Each option represented different trade-offs
between Adobe’s various quality objectives and impacted Apple’s goals differently.
These are represented in figure 1a via different satisfaction or denial labels on goals
and dependencies. These alternatives are labeled as α (translation) or ß (comingling) to
differentiate label values that are propagated to other model elements.</p>
      <p>The translation option (α) was preferable for Adobe over the comingling option (ß)
because a drawback of the comingling option was that many extant Flash-based apps
would need to be fitted with Objective-C code by developers. This would limit the
reusability of Flash-based apps across platforms. It could also fragment the developer
community into groups for iOS oriented developers and non-iOS oriented developers.
However, the translation option also suffered from a drawback because Adobe would
need to maintain stability of translated apps over time. It would need to guarantee
compatibility between Flash-based apps that were translated to Objective-C apps using its
IDE on different iOS versions. This could be a costly endeavor for Adobe.</p>
      <p>Apple was the second-mover in this case since it needed to respond to Adobe’s move
(i.e., its decision of α or ß). Apple operated its iOS App Store unilaterally and needed
to decide whether to respond to Adobe's move in a favorable or hostile manner? It could
act favorably by allowing translated apps or comingling of Objective-C and Flash code.
Alternatively, it could act hostilely by rejecting translated apps or disallowing mixing
of Objective-C and Flash code. Apple depended on Adobe for obtaining widely used
apps for its catalog or for its iOS platform to be legitimated by supporting an established
technology (i.e., Flash). However, it had alternatives for each of these dependencies
(not shown in figure 1a). These included adding apps from other developers (i.e.,
substitutes for Flash-oriented developers) and supporting HTML5 (i.e., rival of Flash)</p>
      <p>If Adobe selected the translation option then Apple could prohibit or allow translated
apps. As Figure 1b shows, allowing translated apps was not an advantageous option for
Apple because it meant that developers could build iOS apps without using its IDE
(XCode). This meant developers could bypass rules and regulations that Apple had
baked into in its IDE for enforcing security in third-party iOS apps and its App Store.
Figure 1b depicts the relative payoffs for Adobe that are calculated by considering its
goal model from Figure 1a. If Adobe selected the translation option and Apple allowed
translated apps then Adobe would earn a payoff of 2 and Apple would earn a payoff of
-2. However, if Apple prohibited translated apps then Adobe would earn a payoff of -1
(from wasted effort in building a translator) and Apple would earn a payoff of 1.</p>
      <p>If Adobe selected the API option then Apple could permit or block the execution of
translated apps on iOS. Permitting the comingling of code written in multiple
programming languages was not beneficial for Apple because app developers could obscure
functionality coded in Flash within their iOS apps from Apple. For example, they could
hide in-app monetization from Apple by developing it in Flash so monetary transactions
could be conducted on third-party payment gateways. Figure 1b shows that if Adobe
selected the comingling option and Apple supported code mixing then Adobe would
earn a payoff of 1 and Apple would earn a payoff of -2. However, if Apple disallowed
code mixing then Adobe would earn a payoff of -1 (from wasted effort in adding
Objective-C support to Flash IDE) and Apple would earn a payoff of 2.</p>
      <p>Reasoning based on figures 2a and 2b suggests that, given the existing configuration
of alternatives, objectives and dependencies, it was disadvantageous for Apple to allow
Flash-based apps to run on iOS devices regardless of Adobe’s choice (translation via
third-party IDE or code comingling of Objective-C and Flash). Apple intended for its
ecosystem to grow (e.g., by third-party developers contributing apps) and be
legitimated (e.g., by supporting established technologies such as Flash). However, Apple
also intended to avoid exposing itself to vulnerabilities that could accompany support
for Flash-based apps on iOS devices that were translated using third-party IDEs or
developed using programming languages that could obscure app code from Apple staff.</p>
      <p>In the case study, Adobe moved by selecting the translation option (α) and Apple
swiftly retaliated by prohibiting translated apps. This blocked Flash-based apps that
were translated into Objective-C apps using third-party IDEs from running on iOS
devices. This case shows reciprocation in action because Adobe’s move was harmful for
Apple and Apple responded by moving in a way that was damaging for Adobe.</p>
      <p>This logic leads to the inescapable conclusion that Adobe should not have attempted
to bring Flash-based apps to iOS devices using the existing alternatives that it was
considering. This is because the alternatives that it was contemplating would have resulted
in a win-lose situation where it would have gained while Apple would have lost. Rather,
Adobe should have generated new alternatives for creating a win-win situation for itself
and for Apple. An example of a new alternative could be for Adobe to develop a Flash
translator plugin for XCode (not shown). Such a plugin could allow importation of
Flash code into XCode and be translated into Objective-C code in XCode. This could
have allowed Adobe and Apple to satisfy their objectives and avoid TFT actions.
4</p>
      <p>A Methodology for Understanding Strategic Moves and
Reciprocity on Software Ecosystems with i* &amp; Game Trees
We propose a methodology for co-developing complementary i* models and game
trees. This methodology is presented in Figure 2. The artifacts that result from this
methodology can offer a deeper understanding of the relevant decision domain as well
as the problem and solution spaces. This methodology supports the assessment of
winwin strategies to decide whether existing solutions are satisfactory or if new solutions
must be generated and considered.
Start</p>
      <p>Initiate
i* Strategic
Rationale
Diagram</p>
      <p>Initiate</p>
      <p>Game Tree
(i*)</p>
      <p>Who are the
Stakeholders?
Concrete Actors
as Agents</p>
      <p>and
Abstract Actors</p>
      <p>as Roles
(Game Tree)</p>
      <p>Which is the
Focal Player?</p>
      <p>First Mover
(i*)</p>
      <p>What are the
hard objectives</p>
      <p>of each
stakeholder?</p>
      <p>Goals
How can each
objective be
achieved?
(Game Tree)</p>
      <p>Alternatives
as Tasks
Represent
Sequence of
Moves as
Decisions
(Game Tree)
(i*)</p>
      <p>What are the
quality criteria</p>
      <p>of each
stakeholder?
Quality criteria
as Softgoals
What is the
importance of
each quality
criterion?
Priorities
of Softgoals
What are the
impacts of
alternatives on
quality criteria?
Contribution</p>
      <p>Links
Do the Actors
depend on each</p>
      <p>other?
Dependency</p>
      <p>Links
Are quality</p>
      <p>criteria
Satisficed or</p>
      <p>Denied?</p>
      <p>Label</p>
      <p>Propagation
(Game Tree)</p>
      <p>Represent
approximate
relative Payoffs
for Decision</p>
      <p>Paths
Analyze Game
Tree by Looking
Forward and
Reasoning
Backwards</p>
      <p>No
No</p>
      <p>No
Yes
No</p>
      <p>No
(i*)</p>
      <p>Analyze i* SR
diagram by</p>
      <p>Looking at
Satisfaction or</p>
      <p>Denial of Goals
(Game Tree)</p>
      <p>Do relative</p>
      <p>Payoffs indicate
a win-win strategy?
(i*)</p>
      <p>Do existing
alternatives contribute
to a win-win
strategy?</p>
      <p>No
Yes
Yes
Yes
Yes</p>
      <p>End</p>
      <p>Do existing
objectives contribute to a
win-win
strategy?</p>
      <p>Do existing
relationships between
stakeholders contribute
to a win-win
strategy?</p>
      <p>Do existing
quality criteria
contribute to a win-win
strategy?</p>
      <p>Do existing
stakeholders contribute
to a win-win
strategy?
.</p>
      <p>Yes</p>
      <p>The i* model and game tree are co-developed from the perspective of a focal actor
that is contemplating a strategic move that might result in a TFT countermove. In Figure
2, each solid box represents an action step while each arrow represents a connection
between action or decision steps. Dashed boxes represent groupings of solid boxes
pertaining to a modeling technique. Each action step involving elicitation has an outbound
arrow that is used to denote an addition to the model resulting from that elicitation step.
The following guidelines are useful for instantiating an i* SR model and its
complementary game tree in a consistent manner:</p>
      <p>1. A focal actor is unlikely to be fully knowledgeable about the true intentional
structure of its counter-parties. Therefore, goal models of counter-parties are based on
assumptions on the part of the focal actor that are informed by various sources. These can
include past behavior and public comments of those counter-parties as well as market
research and competitive intelligence about them.</p>
      <p>2. The first decision-maker in the game tree is the focal actor. This actor is choosing
among the alternatives that are available to it for initiating a strategic move that might
trigger a TFT countermove. Subsequent decisions are interleaved among the
counterparties and the focal actor based on their relational context. In a simplistic game tree,
decisions could be interleaved among actors in a round robin arrangement of turns.</p>
      <p>3. The relative payoffs to each actor are based on the assumptions of the focal actor.
These numbers serve a purely comparative purpose and their unit of measure is
irrelevant. It is only assumed that each actor prefers a higher or positive outcome to a lower
or negative outcome wherein 2 is preferable to 1, 1 is preferable 0, 0 is preferable to
1, -1 is preferable to -2, etc.</p>
      <p>4. Each unique decision path from the root node to a leaf node on the game tree is
regarded as a strategy. Payoffs denote the value gained or value lost for each player
based on a decision path. Each player independently decides whether a particular
decision path is advantageous or disadvantageous for it based on the value that it can expect
to gain or lose.</p>
      <p>5. A win-win strategy refers to a positive-sum strategy in which each player gains.
This strategy is likely to be accepted by each of the players. When multiple win-win
strategies are available then the strategy with the highest payoffs for all players is likely
to result in a stable equilibrium as each player would be maximally better off with it. A
win-lose strategy refers to a zero-sum situation in which some players gain at the
expense of other players. A lose-lose strategy refers to a negative-sum situation in which
all players lose. Both win-lose and lose-lose strategies are unlikely to lead to a stable
equilibrium as some or none of the players might be willing to cooperate.</p>
      <p>6. Payoffs for a player in the game tree represents the idiosyncratic preference
structure and distinctive intentionality of that actor as represented in the i* SR model.
Payoffs can change when the objectives of that actor or the satisfaction of those objectives
change. Relative payoffs are approximated based on the priorities associated with
various objectives as well as their satisfaction or denial.</p>
    </sec>
    <sec id="sec-2">
      <title>Related Work</title>
      <p>
        Two related streams of SECO research pertain to the focal subject. These are: (1)
foundations of SECOs and (2) model-based analysis of SECOs. Researchers have explored
foundational aspects of SECOs to better explain these socio-technical phenomena.
Bosch and Bosch-Sijtsema [
        <xref ref-type="bibr" rid="ref37">37</xref>
        ] trace the evolution of SECOs and their development
within the broader software industry. Popp [
        <xref ref-type="bibr" rid="ref38">38</xref>
        ] classifies business models of software
companies and explains key characteristics. Weiblen et al. [
        <xref ref-type="bibr" rid="ref39">39</xref>
        ] identify marketplace
business models for managing SECOs. de Andrade et al. [
        <xref ref-type="bibr" rid="ref40">40</xref>
        ] investigate performance
measurements for assessing the health and sustainability of SECOs. Idu et al. [
        <xref ref-type="bibr" rid="ref41">41</xref>
        ]
explore categories of apps within the iOS SECO to discern the motivations and strategies
of app developers. Such research about the foundational aspects of SECOs have helped
to establish a consistent and coherent intellectual basis for the study of SECOs.
      </p>
      <p>
        Researchers have also applied modeling techniques for analyzing SECOs.
Boucharas et al. [
        <xref ref-type="bibr" rid="ref42">42</xref>
        ] propose a process for establishing a standard for formal modeling of
SECOs which is useful for communicating, theorizing, and anticipating developments on
SECOs. Fricker [
        <xref ref-type="bibr" rid="ref43">43</xref>
        ] applies concepts from negotiation and network theory to develop
a framework for analyzing SECO requirements. Sadi and Yu [
        <xref ref-type="bibr" rid="ref44">44</xref>
        ] identify a set of
analytical as well as descriptive requirements for SECOs and analyze the expressiveness
as well as analytic capabilities of various modeling languages for supporting those
requirements. Christensen et al. [
        <xref ref-type="bibr" rid="ref45">45</xref>
        ] apply the Business Model Canvas to study the
business logic underlying SECO architectures. Pettersson et al. [
        <xref ref-type="bibr" rid="ref46">46</xref>
        ] apply Software Process
Engineering Meta-model to study domain specific SECO. Such research that applies
established techniques for representation and reasoning to study SECOs has yielded
rigorous and defensible results.
      </p>
      <p>
        Additionally, Gans et al. [
        <xref ref-type="bibr" rid="ref47">47</xref>
        ] propose a TCD (Trust–Confidence–Distrust) approach
for continuous requirements management in inter-organizational networks. Their
approach considers path dependency, history, and strategic dependency between actors
during analysis [
        <xref ref-type="bibr" rid="ref47">47</xref>
        ]. Our work is synergistic to this approach which "combines the
structural analysis of strategic dependencies and rationales, with the interaction
between planning, tracing, and communicative action" [
        <xref ref-type="bibr" rid="ref47">47</xref>
        ].
6
      </p>
    </sec>
    <sec id="sec-3">
      <title>Discussion</title>
      <p>In this paper, we noted that SECOs comprise participants that are engaged in
coopetitive relationships with each other. Within such inter-organizational relationships the
decisions of an actor are supported or constrained by alliance- and network-centric
aspects (e.g., the actions of other actors). We discussed that reciprocity is a common
behavioral response by humans and is prevalent in many inter-organizational
relationships. However, while reciprocation might be a suitable behavior in certain scenarios
there are many circumstances when it is not appropriate. In Section 2, we noted certain
limitations and drawbacks of reflexive reciprocation and autonomic retaliation by
enterprises in coopetitive relationships.</p>
      <p>In Section 3, we showed that, i* and game trees can be used together to express the
logic behind the moves and countermoves of two enterprises in a coopetitive
relationship related to their SECOs. In section 4, we proposed a methodology for
synergistically co-developing an i* SR diagram and a game tree. These complementary artefacts
are useful for comparing various strategic alternatives available for participants in a
SECO.</p>
      <p>Figure 1a demonstrated the characteristics of i* SR diagrams that are relevant for
modeling strategic moves and reciprocity. Alternatives for achieving objectives are
represented as tasks linked to a goal (e.g., Apple can achieve its objective of driving
adoption of iOS devices in the smart mobile device market either by allowing iOS apps to
be coded only in Objective-C or with Ojective-C and Flash). Relationships between
actors are shown as dependencies (e.g., Apple depends on Adobe to supply mobile apps
to its App Store while Adobe depends on Apple for access to its API).</p>
      <p>Contribution by elements to each other are portrayed via help and hurt links (e.g.,
Adobe can reference the Objective-C API and this can satisfy its objective of
optimizing its apps for iOS devices however this can lead to the denial of its objective of
existing Flash apps be supported). Label propagation is used to show the effect of choices
by Adobe on the available choices for Apple through a cascading satisfaction or denial
of relational elements (e.g., Adobe translating Flash code to Objective-C code on own
IDE will lead to the denial of high priority objectives of Apple which are to centralize
revenue from apps and control security of apps). Task decomposition is used to show a
hierarchy of objectives and alternatives (e.g., Apple can allow Objective-C code only
but do so by mandating XCode as the only supported IDE or by supporting third-party
IDEs as well).</p>
      <p>In section 3, we noted that i* is useful for performing evaluative as well as generative
analysis. i* provides representation support for exploring and elaborating on the
problem understanding as well as the solution space. i* models support the evaluation of
existing problems and solutions that are already represented as well as the exploration
of new problems and solutions that need to be generated. This is in contrast to typical
search algorithms on game trees that assume that the problem space is fully known, and
that the solution space is given and fixed.
7</p>
    </sec>
    <sec id="sec-4">
      <title>Conclusion and Future Work</title>
      <p>This paper presents novel work because it proposes a modeling-based approach for
analyzing strategic moves and reciprocity in coopetitive relationships on SECOs. We
posit that i* is well suited for analyzing and solving optimization problems on game
trees because it supports the analysis of tradeoffs between alternatives in terms of
quality objectives. i* supports the depiction of softgoals that can be used to compare the
impact of each alternative on an actor’s objectives. It also supports the representation
of dependencies among actors that serve as sources of opportunities/vulnerabilities
thereby supporting/constraining different courses of action between them.</p>
      <p>A limitation of i* is that it lacks support for representing negative dependencies. i*
does not support the discrimination between the omission of dependency (i.e.,
dependency is not depicted in an i* diagram) and the lack of dependency (i.e., no dependency
exists between actors). Modeling reciprocity necessitates the means for representing
lack of dependency because this can have an impact on the decision-making process of
an actor. Lack of dependency on another actor may give more flexibility to an actor
while absence of a dependency may reflect a choice by the modeler to elide certain
model elements. Extending i* to express the distinction between absence of a
dependency and a lack of a dependency will aid the ability to develop more thorough models.</p>
      <p>Validating our approach of jointly using i* and game trees further is a part of future
work as is representing and reasoning about the temporal dimension of reciprocity. The
approach that is presented in this paper can be tested by applying it to additional
published case studies. It can also be tried in the industry through empirical case studies in
organizational settings. It can also be critiqued by enterprise modeling practitioners that
are familiar with the use of decision-support tools such as game trees.</p>
    </sec>
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