![](bg2.png)
analysis and quantitative calculation. The basic ideas
of the AHP method to solve problem are as follows
(Teng Shaoguang, 2005): Firstly, we decompose the
problem to be different factors according to the
nature of the problem and objectives to be achieved.
Secondly, we stratified the factors to be a
hierarchical structure model according to the
relationship between factors. Thirdly, we analyze the
problem in accordance with the level of the factors.
Last, we get the importance weights of the lowest
level of factors by reference to the highest (which is
the total goals) level of factors.
Teng Shaoguang used the AHP method to
construct a hierarchical structure of the factors that
influence the public traffic in his paper
“Comprehensive analysis of AHP for the factors
affecting the public transport". He proposed to
analyze the importance of various factors by the
AHP method t. At last he got the relative importance
of various factors and ranked them (Wang Hongyu,
2009).
(2) Structural Decomposition Analysis
The SDA, which is short for "Structure
Decomposition Analysis", was first proposed by
Leonfief the research on analysis of the American
input-output charts. SDA's basic idea is to divide the
change of one target variable into several changes of
different elements so that we can identify the degree
of the influence of the various elements. Besides, we
can also carry on the decomposition step by step
according to the need. Ultimately, we can
distinguish the influence degree of the target
variable of the various factors (Zhu Xianghua,
2008).
Both of the two methods above can quantify the
qualitative issue. We can use these two methods to
get the relative importance of the factors. It is
helpful to grasp the key factors, but the relationship
and the mechanism between these key factors are
not clear. It is negative for us to find the source of
the problem. So we have to introduce the causal
analysis method.
2.2 Method of Causality Analysis
At the process of exploring and understanding the
world, we always want to answer the 'why' question.
That is, we want to find the factors and information
to explain the phenomenon. Because of searching
the relatively constant causal mechanism under the
phenomenon, we have the possibility to get and
accumulate our knowledge. In general, the
development of social science research is always
around the "discovery issue", "understand the
problem" and "solve the problem ". As we know,
only the "discovery issue" is not enough to the
progressing of our society. And we should find the
factors under the phenomenon as the entry to solve
the problem. Given the validity of causal analysis
and Based on the conclusions of the causal analysis,
we can predict the future events that may occur
under what conditions and find the means of
controlling them, which provide the method to
develop strategies and to improve our society.
Therefore, causal analysis is the key to the social
science research (Wang Tianfu, 2006).
2.2.1 Introduction to Causality Diagram
Causal analysis is demonstrated through the
Causality Diagram, also known as the special causal
diagram, Fish Bone Figure and Tree Figure.
Causality Diagram is a mapping method to produce
the cause of the problem through the gradual in-
depth study. Causality Diagram establishes the
priorities of the cause of the problem based on the
causality relationship, and display them in the event
generation process, so as to make an intuitive
understanding of the problem for the project
managers. Causality Diagram is a method to find the
basic reason of the problem, each "fishbone"
represents the cause of the problem. A problem is
often caused by a variety of reasons, which can be
showed with the graph of trunk, large branches, the
branches and twigs according to their importance.
So we can understand the problems at a glance and
system. The Causality Diagramcan helps
policymaker’s analysis of the nature of the problem
in-depth, develop strategies and achieve the purpose
of pre-control.
The Causality Diagram applies for analysing the
causes of traffic problems, which has intuitive and
logical features and so on. What’s more, it can
analyze accident overall, analyze individual reasons
and even the specific case.
2.2.2 Making Causality Diagram
(1)Working group including Responsibility Person
for this issue and other human who have the
relations with it, Responsibility Person should have
rich instruction and leadership experience, Joint
effort from us should be taken to create the friendly,
equal, relaxed environment.
(2)The person in charge of the project will identify
ICEIS 2011 - 13th International Conference on Enterprise Information Systems
558