The amount of water that plants need depends on many factors, including the growth habit of the plants, soil type, nearby plants, and climate. It's nearly impossible to assign a standard amount of water to apply. If you can, group plants with like water requirements on the same programmable zone. For example, group lawn areas so you can program a set amount of water for them. Shrubs require less water than turf and should be on a separate zone.
Also consider the exposure of the planting area when setting up watering zones. Plants on the south or west sides of a building will require more water than those growing on the north. This process of mapping out the zones might seem daunting, but it is critical for an efficient system. Once your zones are established, experiment with run times and water application until you find a proper balance. You'll soon get a feel for what run times work best at which times of the year and for which parts of the yard.