This paper attempts to clarify the actual features of the decentralizing trend of the software industry through the development of large corporations' software houses.
First, in order to confirm the decentralization of the software industry in Japan, changes in the distribution of employees after the 1980's were analyzed.
Second, with special reference to the five largest corporations mainly manufacturing computers and software, the development and distribution and the locational trend of their software plants are analyzed, using data from interviews and questionnaires.
Third, in order to clarify the locational trend of each software plant, the plants whose data can be used are classified in five categories. Then, the relationships between the distribution of software houses, regional labor markets and branch offices are examined.
The main findings obtained can be summarized as follows:
1) The Japanese software industry achieved rapid growth in the 1980's. In the process of growth, the employees of the software industry were concentrated in the Tokyo metropolitan area, but the growth rates of such regional central cities as Sapporo, Sendai, Hiroshima and Fukuoka were especially distinguished and in Japan a decentralizing trend in the software industry is in progress.
2) The software houses of the five largest corporations mainly have been located in the three metropolitan areas (Tokyo, Osaka and Nagoya), and in the four regional central cities. These seven areas are very important regions as footholds for the software producing sectors of the corporations, as shown in Figure 3.
3) The software houses which mainly produce control systems for distribution, manufacture, and other systems and have been located in major metropolitan cities, while the houses which mainly produce special computer systems and services for the customer are usually specialised to the business for their customers and manufacture nothing else. Most of them have been located near the customers rather than in metropolitan cities.
4) In the eastern part of Japan, the employees of each software house mainly come from the Tokyo metropolitan area. However, in the western part of Japan, the employees are not brought from the Tokyo metropolitan area, but local areas, as shown in Figure 4.
5) Many software houses of the corporations have often been located in the cities where the branch offices organized by the same corporation have been also located.