SEKE 2012 Proceedings - Knowledge Systems Institute

Take basic requirements
from user as main goal
Perform requirement
analysis and represent
it in the form of Goal
Graph(Input to system)
Suggestions to the requirement analyst
(Output)
Semantic Mapping
Verification Module
Domain Ontology
(Input)
Automated System
Verification Metrics
1. Completeness
2. Correctness
3. Conflict
Fig. 1: Architecture of the proposed Automated System
IV. PROPOSED METHODOLOGY
Figure 1 represents the architecture of our proposed automated
system. In [13], we have proposed the architecture
of an automated system which generates the system design
from the requirement specif cation by consulting the Domain
Ontology of the system. But, this architecture lacks to verify
input requirements. Designing the architecture of the system
without ensuring that the requirements are in correct form
may lead to the development of inconsistent systems. So,
the verif cation module has also been included to be a part
of our automated system. Thus, the automated system takes
the requirement and the Domain Ontology as input, verif es
these requirements against Domain Ontology, and suggests
the system analyst to change the specif cation accordingly.
In our automated system, we have peformed goal oriented
requirement analysis and represented the requirements in the
form of Goal Graph. The Domain knowledge is represented as
Domain Ontology. The leaf level sub goals are taken as input
to the automated system and mapped to concepts in Domain
Ontology and verif ed against them.
A. Requirements represented by Goal Graph and Domain
Knowledge represented by Ontology
Agents in MAS are goal oriented i.e. all agents perform
collaboratively to achieve some goal. Goals have been used
in Software Engineering to model requirements and nonfunctional
requirements for a software system. Goal Graph
and Domain Ontology have been def ned in [13].
B. Semantic Mapping from requirements to Ontology
The process by which the basic keywords of the leaf node
sub goal are mapped into concepts in the Ontology is called
Semantic Mapping. In this paper, the aim of semantic mapping
is to f nd out tasks from Domain Ontology, required to be
performed to achieve a sub-goal given as input from the Goal
Graph. Let a user requirment R come to our proposed system.
After goal oriented requirement analysis of requirment R, we
represent it as a goal graph and get a set of leaf level indivisible
subgoals. These leaf level sub goals are represented as:
G0= {G1 , G2,...,Gp }.
(Output)
Let there be a set denoted as G={g1,g2, ...,gq }. Each gi ∈
G is another set which consists of set of goal-concepts which
are associated with a consists-of relationship in ontology. Let
us denote each gi ∈ G as ”concept-set”.
Let Ky be a function that maps a subgoal to its basic
keyword set. The set of keywords for subgoal Gi ∈ G0 can
be represented by Ky(Gi) ={Kyi1,Kyi2 ...Kyij}. Letfbea
mapping which maps each Ky(Gi) or some Ky(Gi) ∪ Ky(Gj)
∪ ...∪ Ky(Gk) to a concept-set in ontology, Gi ∈ G0 where
1≤ i ≤ k or {Gi, Gj ,..., Gk }⊆ G0.
i.e. f(Ky(Gi)) = gi, gi ∈ G, or there exists a subset of G0,
{G1 , G2, ..., Gk }⊆G0 such that f(Ky(G1) ∪ Ky(G2) ∪ ...∪
Ky(Gk)) = gi.
Each subgoal Gi ∈ G0 or some set {Gi, Gj ,..., Gk }⊆ G0
is mapped on some concept-set gi ∈ G.
C. Verification metrics of requirement analysis
In this paper we have def ned three metrics for verif cation
of requirment analysis.
• Completeness
• Correctness
• Conf ict
1) Completeness:
• Case 1: Each keyword in the keyword set KY= Ky(G1)
∪ Ky(G2) ∪ ...∪ Ky(Gp) is mapped into some concept
∈ concept-set gi of ontology. If a keyword ∈ KY can be
mapped to a concept in concept set gi of ontology, then
add the keyword to set S and add the concept set gi to
ST. Thus, ST=ST ∪ gi, where initially ST is the empty
set.
Repeat this step for every keyword in KY. Finally, the
Measure of Completeness, MCOM = |S|/|T|
• Case 2: Let G={g1,..., gq }be the set of concept-sets on
which G0 is mapped. Let T i be the set of tasks associated
with gi ∈ G with consists of relation. So, T 0= T 1 ∪ T 2
∪ ...∪ T q is the set of all tasks that are required to be
performed to achieve the goal set G0.
Let pred(ti) represent the set of tasks that should happen
before ti and succ(ti) represent the set of tasks that
happen after ti. So, for each task ti ∈ T 0, check the
following condition
∧
{pred(ti)⊂ T 0 succ(ti) ⊂ T 0 }= true.
For all ti where the above condition is false , let pred(ti)
∈T’i or succ(ti) ∈T’i. LetT ′ i be associated with g ′ i ∈
G by the consist of relation. The sub goal formed by the
concept-set gi should be included in the suggestion list.
2) Correctness::
• Case 1: Each keyword in the keyword set KY= Ky(G1)
∪ Ky(G2) ∪ ...∪ Ky(Gp) should be mapped into some
concept ∈ concept-set gi of ontology. So, total number
of keywords in requirement analysis is m2= | (Ky(Gi)
∪ Ky(Gj) ∪ ...∪ Ky(Gk))|. If a keyword ∈ KY cannot
be mapped to a concept in concept set gi of ontology,
then add the keyword to set US ,where initially US is the
empty set.
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