Many companies initiate programmes containing continuous improvements (CI) and work development (WD), but a lot of those fail in terms of sustainability. The paper identifies important factors that need to be considered urgently if one wants to reach a sustainable work with CI and WD. The factors include aspects such as basic ideas, personal interest, simplicity, active management, structured work, clear goals and adaptability. These factors are then illustrated by two engineering companies that have been working with CI and WD for two to three years. The outcome of this test confirms that the identified factors are important.