Today’s working life is constantly changing, and work environmental risk factors can alter swiftly. Besides the traditional physical work environment risk factors, somewhat more abstract organizational and social work environment factors also play an ever-increasing role, both in preventing and causing work-related illness. This requires a preventive work environment management that can respond to rapid changes, and where the assessment and remedies rely more on employee participation than on predetermined threshold limits. This study aimed to investigate if the use of a support model (the Stamina model) for workplace improvements could render the same positive effects in quantitative measures that have previously been shown in qualitative studies. Employees from six municipalities used the model for 12 months. They answered a questionnaire at baseline and after six and 12 months, to detect any changes in how they characterized their current work situation and perceived their influence, productivity, short-term recovery, and organizational justice. The results showed that employees felt more influential in work situations related to communication/collaboration and roles/tasks at the follow-up compared to the baseline. These results are consistent with previous qualitative studies. We found no significant changes in the other endpoints. The results strengthen previous conclusions, namely that the Stamina model can be used as part of inclusive, modern, and systematic work environment management.