Cyber-Planners were used by the Cybermen to create and direct battle plans and strategies.
In the 20th century, the Cyber-Planner was approximately six feet tall and consisted of a framework of metal and transparent tubes with a number of lights and a rotating head section, completely immobile and concealed in a secure place.
The shape of Cyber-Planners differed between the 20th (TV: The Invasion) and 21st centuries. The later "head" section had a more a bulbous, egg-like appearance (TV: The Wheel in Space). The Cyber-Planner's consciousness could take over the mind of an organic life-form and use the knowledge and capacity within to fulfil its function. The minds of children in particular were targeted for their imaginative potential. (AUDIO: The Girl Who Never Was, TV: Nightmare in Silver).
The Cyber-Planner gathered data from a large variety of sources. It could scan local media transmissions and even channel data from certain human subjects. It used this data to formulate strategies and make decisions based upon probability of success.
The first Cyber-Planner was formed when the Central Committee of Mondas abandoned their individual personalities and funnelled their collective intelligence into a mechanical shell. This Cyber-Planner was sabotaged by the Fifth Doctor, who poured wine into its nutrient vats, severely impeding its thought processes. It was later destroyed by a swarm of Cybermats, which had been reprogrammed by the Doctor. (AUDIO: Spare Parts)
Years before, Tobias Vaughn had a Cyber-Planner (known as the Cyber-Director) installed in his office at International Electromatics in London where it acted as a communications channel between Vaughn and the Cybermen. (TV: The Invasion)
Later when another Cyber-force attacked Space Station W3, after Zoe Heriot was returned there by the Time Lords, the Cybermen, noticing her superior intelligence, planned to convert her into a Cyber-Planner. This failed when the conversion machine, unlocked the locks the Time Lords placed on Zoe's mind, and she piloted the fleet into the Land of Fiction. Whilst in the Land, the Cyber-Planner of the fleet, commanded the Cyber-attack on the Land. It was later destroyed when Zoe and the Sixth Doctor reprogrammed a Book Worm to make the Cyber-planner believe that Cybermen didn't exist, and due to the nature of the Land of Fiction, it blipped out of existence as well. (AUDIO: Legend of the Cybermen)
A Cyber-Planner led the Ninth Cyber Legion to invade Earth in London during 2012. The Cyber-Planner used a piece of the Eternity Clock to power the Cyberfactory. The Eleventh Doctor and River Song destroyed the Cyberfactory, along with the Cyber-Planner and the Ninth Cyber Legion and collected the piece of the Eternity Clock. (GAME: The Eternity Clock)
The most clever Cyber-Planner calling itself Mr Clever was created from the Eleventh Doctor during the battle on Hedgewick's World. At first the Cybermen targeted the Doctor's companions Artie and Angie, for the creative potential of the childrens' minds. After discovering the Doctor, the Cybermites instead partially converted him, giving him a Jekyll & Hyde-like mind. Clever and the Doctor fought for control of the Doctor's mind. With the Doctor threatening to use regenerative energy to destroy Clever, they decided to play a game of chess to determine who deserved control. However the Doctor distracted Clever by claiming he could win the chess game in three moves, then used an EMP to rid his mind of Clever, and the Emperor of the Galaxy had the planet destroyed, destroying the Cyber-army. (TV: Nightmare in Silver)