'demand for improvement' is correct and usable in written English.
You can use it in various contexts to emphasize that someone needs to fix something that is wrong or deficient. For example, "The customer was unhappy with the service and demanded for improvement."
For this reason, there has been a strong demand for improvement in their accuracy.
In recent years, there has been an increased demand for improvement in the appearance of natural teeth.
Considering the demand for improvement of monitoring the elders' states of health, various kinds of intelligent medical devices have been designed by health care industries recently.
As a result, there is a demand for improvement of the methods employing summary birth history data to produce more accurate as well as subnational estimates of child mortality.
"There is a huge demand for improvement". Government reports have identified an estimated $1.7 trillion backlog in surface-transportation repairs — and state and federal governments don't even have enough money to adequately inspect bridges to determine which are most at risk.
MTA [14] found that cleanliness had received a high attention from the subway user and the demand for improvement in cleanliness was overwhelming.
This study's findings provide quantitative information concerning the demand for improvements in agroecosystem services through agri-environmental protection programmes.
Therefore, there is a pressing demand for improvements of existing vaccines with particular reference to higher efficacy and undisputed safety profiles.
The case study shows that industry implemented pragmatic solutions for dealing with P-IT integration into EA, but there is a clearly expressed demand for improvements and a need for refined EAM standards in this context.
Further strengthening of biomedical Co−Cr−Mo alloys is desired, owing to the demand for improvements to their durability in applications such as artificial hip joints, spinal rods, bone plates, and screws.
Politicians have already considered (and abandoned) more than 50 draft versions of a law on domestic violence since the early 1990s, but this time there is muted optimism from campaigners, who say a series of high-profile cases are finally bringing this hidden issue into the open, strengthening demand for improvements in the way complaints from women are handled.
