Understanding and Using the Storage Efficiency Ratio (SER)
Using SER for Evaluating Warehouse and Factory Storage Methods
Effective utilization of storage space is critical for optimizing warehouse operations, reducing costs, and maximizing efficiency. The Storage Efficiency Ratio (SER) is a Key Performance Indicator (KPI) designed to evaluate storage efficiency across different storage methods, including ground-level storage, conveyor rows, and pallet racking systems. This bulletin provides a detailed overview of the SER, its calculation, and how it can be used to assess and improve warehouse storage efficiency.
The SER Formula and Components
The SER formula evaluates how efficiently a storage area is used relative to the total space available, incorporating both horizontal and vertical utilization. The formula is:
Key Elements of the Formula:
1. Total Product Footprint Area:
- Represents the cumulative footprint area (in square meters or square feet) of all products stored within the allocated storage space. This metric includes the actual dimensions of each product stored, providing an accurate measurement of the space occupied.
2. Total Allocated Storage Area:
- This refers to the total floor space dedicated to storage, encompassing not only the occupied area but also any wasted space such as gaps between conveyors, underutilized widths, or aisles in pallet racking setups.
3. Level Utilization Factor (LUF):
- This factor adjusts the SER to account for vertical storage efficiency. It varies based on the type of storage method used:
Ground-Level Storage: LUF (Level Utilization Factor) = 1, as its single-level storage.
Conveyor Rows: LUF varies based on how effectively the conveyor's working surface width is utilized compared to its total footprint. For example, if motors, electronics, or support legs take up 40% of the conveyor's footprint, then LUF = 0.6.
Pallet Racking: LUF equals the number of usable vertical storage levels. For instance, if a pallet rack has 4 levels, LUF = 4.
Examples of Applying the SER
1. Ground-Level Storage:
Scenario: Products are stored directly on the floor or in side-by-
side rows of conveyors.Calculation: Since only one level of storage is possible, the LUF
remains 1. For example, if 300 m² of product footprint occupies a
500 m² storage space:
This indicates 60% of the allocated space is effectively used.
2. Conveyor Rows:
Scenario: Products are stored on conveyors that have
some gaps or wasted space between them.Calculation: Suppose products occupy 80 m² a conveyors
systems working surface of 150 m², and a
This suggests significant underutilization, prompting potential layout improvements.
3. Pallet Racking:
Scenario: Products are stored on multi-level pallet racks,
utilizing vertical space.Calculation: Assume 400 m² of product footprint stored
across 5 levels, with a total allocated floor space of 1000 m²:
This high SER reflects efficient use of vertical storage, maximizing
space utilization.
Interpreting the SER
The SER offers insights into how effectively warehouse space is used and highlights areas for potential improvement:
SER close to 1: Indicates optimal space utilization, with minimal wasted space. This is ideal for operations aiming for high efficiency.
SER below 1: Suggests underutilization, where significant portions of the allocated space are not effectively used. Such scenarios indicate opportunities for reorganizing storage layouts or employing more efficient storage methods.
SER above 1 (with LUF): Common in multi-level pallet racking, indicating highly efficient use of vertical space relative to the floor footprint.
Benefits of Using SER
Comprehensive Analysis: Incorporates both horizontal and vertical storage factors, offering a complete view of storage efficiency. As well as being able to easily compare and benchmark across sections of a Warehouse or multiple warehouses.
Versatility: Applicable across different storage methods, making it a universal KPI for warehouses with mixed storage solutions.
Actionable Insights: Identifies inefficiencies in storage layouts, enabling targeted improvements to maximize warehouse capacity. Informing how storage or conveyor layouts can be optimised or the impact of changes.
How to improve your SER
Remember: Achieving an optimal SER is not just about maximizing space but ensuring that your warehouse operates as efficiently and cost-effectively as possible.
The Storage Efficiency Ratio (SER) is a valuable KPI that helps you gain a deeper understanding of your warehouse’s storage efficiency by considering both horizontal and vertical utilization. Whether dealing with ground-level storage, conveyors, or pallet racking, the SER provides a fair and comprehensive measure that helps guide informed decision-making for effective material handling. The first step to improving your SER is to calculate it in your space(s) and then commit to improving it. Continue to experiment and use virtual models to test configurations. Exploring solutions for storage and material handling that focus on optimising efficiency through this metric is the most sound way to extract real benefit and cost saving in your operation. Tetrisize modular IDBMs are designed to create maximum, versatile storage and handling in spaces. Suitable for horizontal and vertical storage maximisation. Updating the core of how you handle and store industrial materials is the best way to drastically improve your SER.