"quality deterioration" is correct and usable in written English.
It is used to describe a decrease in the quality or standard of something. You could use it in the following example sentence: The company experienced a significant quality deterioration after migrating to a new software system.
Continuing quality deterioration has made airline travel one of the most stressful experiences.
Furthermore, this treatment extends fresh storability without physical quality deterioration.
Rossoll, D. et al. Ocean acidification-induced food quality deterioration constrains trophic transfer.
Yet, does physical quality deterioration of streetscapes affect the livability degradation of urban spaces?
Our research seeks to identify ways to make rural populations – vulnerable populations, in particular – more resilient to air quality deterioration.
Soil quality deterioration and consequent reduced productivity characterize the Vertisols in the highlands of Ethiopia.
Power quality deterioration is due to transient disturbances and steady-state disturbances.
Agricultural nitrogen loss becomes an increasingly important source of water quality deterioration and eutrophication, even threatens water safety for humanity.
It emphasizes that the responsibility for the power quality deterioration should be shared between the supplier and the customer.
Indeed, the paper did warn that "the subprime segment of the U.S. housing market is showing signs of credit quality deterioration" and that the problem could "deepen and spread to other markets".
"The credit quality deterioration at Sears has been similar to that experienced by other issuers during the soft economy of the past two years," said Richard B. Shane Jr., an analyst at Jefferies & Companies, in a research report published yesterday.
