Factor X: Measuring Improvements in the Environmental Efficiency of Products

Index Based on the Product Value and Environmental Impact

Factor X is an index that quantifies the idea of maximizing product value while minimizing impact on the environment. "X" is a value that compares a new product to a baseline product. The larger the X value, the greater the improvement in product performance and the lower the environmental impact. For example, a factor of "4" indicates a fourfold improvement in environmental consideration.

Our calculation of Factor X was originally based on three elements: the reduction of input resources, the reduction of energy used in production, and the avoidance of emission of substances with potential environmental risks. We have since added to these the level of product performance improvement. After we reviewed this formula, we changed the base year from 1990 to 2000, as well as using lifecycle CO2 emissions in place of energy consumed. Mitsubishi Electric now bases the index on these new rules.

Basic Concepts when Calculating Factor X

diagram: Factor Calculation
  • Comparison between a new product and a baseline product (in principle, we use Mitsubishi Electric products and a base year of 2000).
  • Evaluations of the performance factor (improvement in product performance) and the environmental impact factor (degree of environmental impact reduction) are multiplied together to produce the rating.
  • The performance assessment index is evaluated as follows: [Basic functions (product functions, performance, quality, etc.) × product life]. Environmental impact is based on MET, and includes these three indices: (1) volume of non-recycled resources used*1, (2) lifecycle CO2 emission*2, and (3) substances with potential environmental risk. With the index of the baseline product being one, the environmental impact of the evaluated product is calculated, and integrated into the vector sum.
  1. *1 Index for volume of non-recycled resources used = virgin resource consumption + non-recyclable volume (i.e., volume disposed of without being recycled) = [weight of product - volume of recycled materials and parts] + [weight of product - recyclable volume]
  2. *2 CO2 emissions calculated from the point of the procurement of the product to its disposal (previously the amount of energy used in production only).