AD&D accessory. TSR part # 9234. 1988 by Harold Johnson and Aaron Allston.

Book I: Adventure Design: theory and elements
Book II: Forms: blank adventure design forms to flesh out and organize adventure elements.
Book III: Adventure Cookbook: Random adventure generation tables and more theory.

The DM’s Design Kit was a decent intro to adventure design for the novice game master, and has a few ideas even for veteran campaign designers. The random adventure generation system is (predictably) limited; running an entire campaign as a string of randomly-generated adventures is not advised.