Model Planning

This is the use of models to represent the areas used to make plans, given that such things are easier when people have the context of an area to see what to do.

Of course, the Unspoken Plan Guarantee means the plan rarely works as expected. But it still lets the audience not only know the plan, but also have an idea of what's happening when things go wrong.

A miniature is one of the most common forms of model for this, but CGI models are getting more common. Sometimes the model can even be 1:1 scale, usually if precision in the plan is a must.

In Real Life, relief maps were not widely used in the 17th and 18th centuries, so models were common—especially when it came to military engineering, where a model was a must-have if you were building or besieging a fortress.

The Big Board and Planning with Props are Sister Tropes, which often overlap with this.

A Sub-Trope of Only a Model.

Compare Exposition Diagram.

Examples of Model Planning include:

Film -- Animated

Disney's Mulan has one, when the general describes the planned advance to his son.

Film -- Live Action

A Running Gag in the Back to The Future trilogy: Doc Brown builds elaborate models of city blocks or canyons to demonstrate his plans to Marty, then apologizes for "the crudity of the model". It also catches on fire, repeatedly.
The Death Star attack plans in the Star Wars films A New Hope and Return of the Jedi are with CGI models.
In Entrapment, the protagonists plan a heist using yarn to practice navigating a Laser Hallway.
The plan in The Dirty Dozen is largely with a model (and a Mickey Mouse figure).
The Ocean's Eleven remake has the thieves building an exact, full-size replica of the vault they're planning to rob for practice.
In the remake of The Italian Job the thieves build a replica practice course in a warehouse to practice driving their escape route, and also have a CGI animation on their computer of the car as if it were traversing the actual route in real time for no apparent reason.
In Top Secret, what begins as Planning with Props segues into this.

Literature

The Reveal in the film of The Kennel Murder Case (S S Van Dine) involves this.

Live Action TV

Models are used to plan attacks in Battlestar Galactica.
Inverted in The Gil Mayo Mysteries, where the team debates possible solutions to the weeks murder(s) by playing with models. The same eclectic set of models is used each week, so they bear no real resemblance who they are meant to represent. Except for that one time when the Reverend Beaver was represented by, of course, a beaver.
"The Architect Sketch" on Monty Python's Flying Circus has an architect who represents his plans for an apartment building with a model that gradually collapses as he gives his presentation, and then spontaneously catches fire. He gets the contract anyway, because he's a Freemason. Or possibly because his competitor's plan involved corridors of rotating knives.

Video Games

One of these is used to plan a casino heist in Saints Row 2. Then your gang decides to ignore the carefully-crafted plan and just "shoot the motherfuckers that are between [them] and the money", a Take That to Grand Theft Auto: San Andreas, where a long series of quests are taken to plan and prepare a casino heist.
In Final Fantasy VIII the La Résistance group Forest Owls used train models to explain the hijacking the railcar of an enemy president.
Antonio in Assassin's Creed II has a model of the Venice rooftops in his office in the Thieve's Guild.

Web Comics

Used extensively in Erfworld.
Order of the Stick has one with miniatures before the battle for Azure City.
The Last Days of Foxhound planned their fight with Solid Snake with clue pieces.

Western Animation

A few episodes of The Simpsons have this, such as when they tried to use a rocket to stop the comet in "Bart's Comet". Each time, the model ends with Moe's Bar destroyed in flames.