Engineered Systems, Nov. 2016, by Mark Bandini, Ernie Brandusa, and Carlos Petty.
http://www.esmagazine.com/articles/98002-chiller-plant-optimization-improving-on-variable-primary-flow-chilled-water-system-operation

"The larger or more complex a cooling plant becomes, the more challenges to its efficiency it will face. When applied wisely, modern controls and equipment can rise to meet those challenges. Read up on active balancing, pump dynamic differential setpoint control, and more responsive tactics for when the worst thing you can do is just go with the flow."