The phrase "not producing" can be replaced with a variety of synonyms that convey the same idea. One option is "unproductive," which suggests a lack of accomplishment or success. Another possibility is "ineffective," which implies that efforts are not yielding the desired results. Similarly, "inadequate" suggests that what is being done is falling short of expectations. Alternatively, "nonproductive" indicates that work is not contributing to the overall goal. Lastly, "barren" suggests a lack of creativity or fertility, while "fruitless" implies a complete lack of accomplishment. Ultimately, all of these synonyms offer alternative ways to describe situations where no tangible results are being achieved.