1. Overview

1.1. Background
Last decade, there increase various digital information, especially spatial information in our life. A car navigation system is one of typical examples. In Japan, we can obtain some information such as running status of trains or shops’ information around where we are. It is increasing the companies and municipalities, which provide this sort of spatial information.

However, we cannot provide this sort of services easily. Nowadays, the installation costs of hardwares and softwares are relatively not so a big problem, because this is just one time investment at the installation. On the other hand, construction and revision of data require huge costs. So this investment for data is must more big problem. In addition, if the economical investment obtains adequate performance, in some case, the installation plan will be rejected. The reason is the endeavor to maintain data will be expected quite heavy.

Consequently, in the early step of use of spatial information (SI), development of a Spatial Data Infrastructure (SDI) is required to promote currency of SI and enlargement of spatial information industry.

1.2 Purpose
Therefore, in this study, we finally aim to develop a methodology to design a data architecture of SDI, effectively and efficiently. To archive this goal, we divide it into step. The first is “development of ACTIVITY-based Domain Analysis (ADA)”. We consider ADA as a methodology to analyze needs for (spatial) information. In this paper, we will discuss ADA. The second is “development of an information use model”. Using this model, we want to simulate the change of activities by the changing of provided information. The last is “development of cost-effectiveness model”. By this model, we aim to estimate the effectiveness of each data item or attribute.

2. Existing Methods – Establishment of common SI-database (SI-DB) for GIS (in Japan)

A common SI-DB has established as a GIS shared data in some division of a city office. In a city office, some division such as Asset Estimation, Road Management and supervision of housing and building has used each GIS. Some data like land lots and road has almost same or relatively close architecture for each other. Therefore, to reduce data construction and revision costs and to support efficient data currency, SI-DB has shared in some city office.

When we establish it, we decide the data architecture as the following steps.

• To list up the data which are used in each division.
• To merge those data list.
• To check out whether they will use each data items or not.
• Finally, to define the data items which will be relatively highly referred.

	Road	Building	Water Boundary	Land Lot Boundary	Railway
Road	O	X	O	O	O
Urban Planing	O	O	O	O	O
Fixed Asset Taxing	0	0	O	X	O

Surely we can extract the data architecture, but this way has some problem. By this way we cannot handle the needs of potential users such as evaluation of assets or risk in finance and insurance industry. The biggest problem is not to be able to handle daily activities. Thus if we design data architecture of SI-DB as infrastructure by this way, it must be biased toward the existing GIS users.

3. Activity-based Domain Analysis (ADA)

3.1 Activity-based domain Analysis (ADA)
ADA is a methodology to design data architecture of common SI-DB. Generally, we have to clarify the requirement on the first process of designing DB. This process is called “Concept Designing”. We use ADA on this process. Analyzing by ADA, we extract the information items and those requirements, which are used by each activity.

3.2 Terminology
In this section we define the terms that are used in ADA.

(2) Activity: An ACTIVITY is defined as an objective of each activity. For example, “To go to a customer”, “To evaluate lots to open a new brunch”. An ACTIVITY can hold a hierarchical structure. This hierarchy is composed of a sub-ACTIVITY and a super-ACTIVITY. Dividing an ACTIVITY into a set of A sub-ACTIVITY.