This item is accessible only under the Model menu. When one or more decision process diamond spaces or sub-model spaces are showing on the Map/Model level, this menu item reads Close Decision Diamonds. Choosing Close Decision Diamonds causes all decision process diamond spaces and sub-models to be put away into their icons. When sub-models or decision diamond structures have been created on the Map/Model level, but all spaces are hidden within their respective icons, Open Decision Diamonds will cause the decision process diamond spaces and sub-model spaces to be opened up. The mechanics of Sub-models are discussed extensively in Chapter 9. Decision Process Diamonds are discussed in Chapter 4.