MRP I was some of the first business software to be widely adopted during the 1970s. Manufacturers sought these systems in order to improve efficiency and accuracy when it came to basic processes such as production scheduling and inventory management.
By the 1980s, manufacturers realized they needed software that could also tie into their accounting systems and forecast inventory requirements. Enter MRP II, which included these integrations in addition to all the capabilities offered by MRP I. Enterprise resource planning (ERP) software features-which we'll cover later on-are included in the following table for comparison.

Reference:
- MRP vs. MRP II: What's the Difference?
- CIPS study guide page 118-119
LO 2, AC 2.3

The concept of a unit load is to create a stable and secure, easy-to-move group of stock that is fast to load and unload from vehicles.
The advantages of unit load concepts are as the following:
* More items can be handled at the same time, thereby reducing the number of trips required and, potentially, reducing handling costs, loading and unloading times, and product damage.
* Enables the use of standardized material handling equipment.

In a traditional warehouse, storage racks are arranged to create parallel picking aisles, perhaps with one or more cross aisles to allow workers to move quickly between picking aisles. This structure forces workers to travel rectilinear distances (north-south and east-west) to picking locations.

Kevin R. Gue and Russell D. Meller proposed alternative aisle designs:
- The 'Fan' shaped layout (or "Flying V"). This layout maintains parallel picking aisles, but al-lows the cross aisle to take on a different shape. If travel begins and ends at the bottom of the V, Gue and Meller expected distance to retrieve a single pallet is 10% less in this warehouse than in an equivalent traditional design.
- The Herringbone-shaped layout (or commonly referred as Fishbone layout) combines the verti-cal picking rows of a traditional warehouse with a second set of horizontal picking rows, divided by a V-shaped diagonal alley crossing the entire warehouse. This simple modification to the typical warehouse design allows employees (e.g. a forklift driver) to increase travel speed between picking locations. Efficiency gains achieved through a layout reconfiguration would reduce picking cost up to 23% compared to an equivalent warehouse using a traditional configuration.

Reference
Aisle Design - Kevin Gue
LO 1, AC 1.1