It is more than 10 years since various computerizing works have been applied in the field of curved shell plates processing. In this period, many kinds of these programs have been developed, and the become to one of the most effective tools of mold loft works. However most of these programs were developed separately, so it can be said that there should be some problems in inter communication of data between each programs. In order to solve above problems, the improved integrated system for curved shell plate “SHELL” (SHell Expansion and Logical Layout system) has been newly developed and applied to actual ships. The system is featured by many characteristics as follows ; 1) The offset data such as frame lines, water lines, longitudinals, seams and butts are to be organized by the most suitable co-ordinate which corresponds to the jig at the plate assembly stage. Above process should bring the better result in accuracy of the calculation of the shell plate developments, roll sets for the plate bending, jig tables and final marking plans for the assembly stage. 2) The theory of fabrication of double curved plate such as ships shell is so complicated that not only geometrical calculation but also experimental considerations have taken in account. Then the means of accumulation of feed back data from field should be effective in the application of next sister ship. 3) Many kinds of outputs can be utilized with various usages, such as steel material size list for purchase order, negative film for photo-project marking, punched tape for numerical controlled cutting machine and so on, in accordance with yard facilities.