The Maximum Shape Ratio is the limit value for the shape ratio of a department before it gets penalized in the shape adjusted distance score. The department shape ratio is the maximum of the length to width and width to length ratio of the smallest rectangle that completely encloses the department. For example the shape ratio of a square is one and the shape ratio of a three by one rectangle is equal to three. If a department shape ratio exceeds its maximum shape ratio then it will get penalized. If the department shape ratio exceeds the maximum shape ratio then the shape adjusted distance score is the sum of the flow distance score and the department shape ratio excess over the maximum shape ratio times the Shape Penalty. The term shape factor is also commonly used for shape ratio. The acceptable value of the maximum shape ratio depends on the department function, so each department can have a different maximum shape ratio. Only the block exchange algorithms use the maximum shape ratio to penalize block layouts to avoid excessively narrowly shaped departments.
The perimeter ratio is the ratio of the current perimeter length of a department divided by the perimeter length of a square department with the same area. For rectangular departments there exists a one to one correspondence between the shape ratio and the perimeter ratio. The Maximum Perimeter Ratio is computed from the Maximum Shape Ratio and is an output only variable, it cannot be set by you.