3.3. Overall Structure of the Method
Overall structure of the method proposed
in this paper consists of 4 steps (Fig.1)
-
Modeling Activities and requirements for
information of private companies
- Surveying and modeling demands for
spatial data
- Surveying and modeling costs of creating
spatial data
- Modeling spatial data market and estimating
economical benefit of spatial data infrastructure
From next section, the authors describe each
of the above procedures.
Fig.1 Structure of whole method
4. Modeling Activities and Requirements
for Information of Private
Companies
As a first step of estimating demands for
spatial data, in this research, models are developed,
describing standard business activities
of various kinds of private companies together
with their requirements for information.
To develop such models, the most straight-forward
way is to cover all business activities
by visiting each office and watching business
activities whole day, though it is not feasible
at all. So, in this research, the author introduces
"Activity Domain Analysis" (ADA) help develop
a model of activities of organizations
with requirements for information of each activity
using existing documents as references.
After developing approximate model of activities
of companies, the model is to be
checked through interviews with businesspersons
who understands actual structure of the
business.
4.1. Activity Domain Analysis (ADA)
ADA is a method to extract and classify
activities with its information usages according
to the purposes of each activity. ACTIVITY
in ADA is defined as a group of sequential
activities designed to achieve some goal. An
assumption underlying this method is that purposes
of each activity will not change drastically,
even if styles of activities change with
technical improvement like informational revolution.
Thus ADA can be considered as a
method of describing and modeling activities,
which can easily take various changes especially
in information technologies.
In ADA hierarchical descriptions of activities
are made; from activities with general
purposes controlling whole activities of people
or organizations to subpurposes in order to
achieve general purposes. So, ADA can capable
to describe largescale and complicated
activities.
On the other hand, when arranging information
items required by activities, it is necessary
to describe and assemble relations between
information items after extracting them. In
ADA, required information is described as Application
Schemas which can represents usages
of information and conceptual models in each
activity systematically. .
The followings are the detailed procedures
of an ADA.
- Extract subjects of each business
process (These subjects are called as
ACTORs)
- Extract purposes of daily business
activities of each ACTOR. (The
activities grouped under the same
purpose are called as ACTIVITIEs)
- Disaggregate ACTIVITIEs into more
detailed and smaller items (called as
SUB-ACTIVITIEs. Each SUB-ACTIVITIEs
are for the "sub-purpose"
of the "parent" purpose.)
- Extract requirements for information in
each SUB-ACTIVITY. (These requirements
are called as APPLICATION-SCHEMEs)
- Classify SUB-ACTIVITIEs which have
similar APPLICATION-SCHEMEs
- Integrate APPLICATION SCHEMEs
of typified SUB-ACTIVITIEs
Fig.2 shows the structure and example of
ADA.
Fig.2 Structure and example of ADA
4.2. Confirming ADA Models by
Interview
After developing initial model of business
processes using ADA, the model is corrected
and confirmed by interviewing with persons
who are in charge of actual activities described
in the model.
The author considered the concept of ADA
as difficult to understand for business persons.
When making interviews, the model derived
from ADA is converted as work flow chart
which is wellknown for businesspersons.
5. Modeling Demands for Spatial
Data
After developing models of business activities
and information requirement, we must
create a quantitative model of demands for
spatial data.
5.1. Survey on Demands for Spatial
Databases
To create demand model, firstly spatial information
is to be chosen among all information
required in business processes.
After spatial information requirements are
extracted, the following attributes of these requirements
are surveyed with interviews or
questionnaire surveys.
- Category of required information (c.f.
roads, sewers, etc...)
- Required quality of information
- Maximum investment for such information
- Elasticity of maximum investment with
changes in qualities
Using these values, a quantitative model is
developed.
