Sentence:  The cost of <WSD>developing</WSD> a major weapon system is now so enormous that the greatest care must be exercised in selecting new systems for development , in determining the most satisfactory rate of development , and in deciding the proper time at which either to place a system into production or to abandon it . 
Meaning of the word marked with <WSD> tags:  make something new, such as a product or a mental or artistic creation