enhancement
noun [ C or U ]
uk/ɪnˈhɑːnsmənt/ us/ɪnˈhænsmənt/a change, or a process of change, that improves something or increases its value:
We have made many enhancements to the software that will strengthen system security.
They plan to release a series of new products and product enhancements.
performance/productivity enhancement The measures are intended to be incentives for performance enhancement.
earnings/pension/revenue enhancement