Estimating the Size Parameters of the Storage and Retrieval System

System width, length & height are vital to estimate the size of AS/RS. For this reason, it is needed to determine following parameters:

 (A) Number of Rows & the Number of Bays in Each Row of a System

Number of S/R machines utilized to store and retrieve materials based primarily on the system throughput and the cycle time. S/R machines are utilized for one or more aisles. Every aisle has two rows. Thus, the number of rows in case of one S/R machine per aisle is following:

Number of rows in the system = 2 × Number of S/R machines in the system.

Number of Bays = Number of storage space required / (Number of rows per S / R machine × Number of S / R machines × Number of storage spaces per system height)

Number of storage spaces per system height = System height desired /Storage space height

 The variation in the wanted system height is in among 30 to 90 ft.

 (B) Estimation of Bay Width, Rack Length, System Width, System Length, Bay Depth and Aisle Unit

The length of a single storage space is added up to the centre-to-centre rack support width to calculate bay width. Therefore we get,

Bay width = Length of storage space + Centre-to-centre rack support width

               = l + x + x₁

Here x₁ is the centre-to-centre rack support width

Rack length     = bay width × number of bays

System length = rack length + clearance for (S/R machine run-out + P/D area)

Bay depth       = width of the individual storage space + bay side support allowance

                     = u (b + z) + x₂

Where x₂ is the bay side support allowance.

Aisle unit = Aisle width + (2 × Bay depth)

System width = Aisle unit × Desired number of aisle