SEKE 2012 Proceedings - Knowledge Systems Institute

then extended to “Company Purchase” and “Personal
Purchase”, and the use case “Promote items” is then extended
to “Take Initiative”. Each goal is labeled with R or S (rigid or
soft goal), A or Y (actor-specific or system-specific
requirements), and F or N (functional or nonfunctional
requirements). Lastly, the goal evaluation takes place for
evaluating the relationship between the use cases and goals, the
interaction between goals in the use case level, and the
interaction between goals in the system level.
For analyzing the relationship between the goals and the
use cases in te rms of their degree of relevance, we use four
levels to describe their relationship. A pair of use case and its
corresponding goal is compared to see whether they are highly
relevant (labeled as ++) with each other. Otherwise, they can
be partially relevant (+), partial irrelevant (-), or totally
irrelevant (--) to each other. The result of checking such
relationship based on the example in Figure 4 is recorded in
Table I.
TABLE I.
RELATIONSHIP BETWEEN USE CASES AND GOALS
G1 G2 G3 G4 G5 G6 G7 G8
U1 ++ + + + ++ - ++ ++
U2 + ++ - + + ++ -- +
U3 ++ + ++ + ++ - ++ ++
U4 ++ + + ++ ++ - ++ --
U5 ++ + + + ++ + -- +
U6 + + - + + ++ - +
U7 ++ + + ++ ++ -- ++ --
U8 ++ + + + ++ + -- ++
By analyzing the relationship between goals at the system
level, we state that if both goals are cooperative to each other
for all use cases, then they are cooperative to each other at the
system level. If all of them are conflicting to each other at the
use case level, then they are conflicting to each other at the
system level. We use the concept of cooperative, counterbalanced,
and conflict relationship to describe such interactions,
and the result is shown in Table II.
TABLE II. RELATIONSHIP BETWEEN GOALS
(Co: Cooperative, Bal: Counterbalanced, Conf: Conflict)
G1,G2 G1,G3 G1,G4 G1,G5 G1,G6 G1,G7 G1,G8
Co Bal Co Co Bal Bal Bal
G2,G3 G2,G4 G2,G5 G2,G6 G2,G7 G2,G8 G3,G4
Bal Co Co Bal Bal Bal Bal
G3,G5 G3,G6 G3,G7 G3,G8 G4,G5 G4,G6 G4,G7
Bal Bal Bal Bal Co Ba l Bal
G4,G8 G5,G6 G5,G7 G5,G8 G6,G7 G6,G8 G7,G8
Bal Bal Bal Bal Conf Bal Bal
When comparing the interaction between a p air of goals,
we consider a goal consisting of a set of entries corresponding
to use cases and compare each pair of entries. Thus, using
Table I as example, we check two columns to compare the
entries row by row. If all rows are ++ or +, then the pair of such
goals are cooperative. If each rows have one entry with ++ or +
while the other entry has – or --, then they are conflicting to
each other. If the entries are mixed, then they are called
counter-balanced.
C. Acquisition of Possible Negotiation Issues
We construct a table indicating the information of each goal,
which consists of the category of a goal and the associated
actor along with the information about cooperative, conflicting,
and counterbalanced goals. Based on s uch information, we
identify a possible issue that will be most influential to a goal.
The result is shown in Table III, where we see that the goal G1
is a rigid goal containing actor-specific and functional
requirements. G1 belongs to the actor Boss, and is cooperative
to goals G2, G4, and G5. It is counter-balanced to the goals G3,
G6, G7, and G8, but does not conflict to any other goals.
Because of such characteristics, we identify an issue, Price, as
the most representative issue concerning this goal. The rest of
the issues, namely Eloquence (ability of presentation),
Necessity, Quantity, Quality, and Budget, are derived in the
same manner.
TABLE III.
GOAL ISSUES AND RELATIONSHIP
Category Actor Coop Conf Counterbalanced Issue
G1 R,A,F Boss G2,G4,G5 G3,G6,G7,G8 Price
G2 R,A,F Sales G1,G4,G5 G3,G6,G7,G8 Eloquence
G3 R,A,F Customer G1,G2,G4,G5G6,G7,G8 Necessity
G4 S,A,F Boss G1,G2,G5 G3,G6,G7,G8 Quantity
G5 S,A,F Boss G1,G2,G4 G3,G6,G7,G8 Price,
Quality
G6 S,A,N Sales G7 G1,G2,G3,G4G5,G8 Price,
Eloquence
G7 R,A,F Customer G6 G1,G2,G3,G4
G5,G8
Budget
G8 R,A,F Customer G1,G2,G3,G4
G5,G6,G7
Price,
Quality
With six kinds of issues identified, we can examine the
pair-wise relationship between these issues and take the
geometric mean to define weighted comparison as shown in
Figure 5. A hierarchical relationship is shown in Figure 6 to
organize the information, in which Level 2 shows the possible
issues. Based on these issues, we can derive possible proposals
in Level 3. P roposal A con tains the tw o issues with highest
values: Budget and Necessity; Proposal B adds Price to
Proposal A; and Proposal C includes Quality to Proposal B.
Figure 5. Calculation for deriving weighting for issues.
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