This study investigates what effects employment flexibility have on the business performance in the computer programming, system consultancy and related services. An analysis of the effects of employment flexibility on outcomes of human resource management revealed that companies which had a higher proportion of temporary agency workers and adjusted employment more frequently had higher turnover rates. The study also showed that the higher the proportion of non-regular workers, outsourcing and the easier it was to adjust working hours, the higher the absence rate. Meanwhile, companies that made employment adjustments more often showed higher defect rates and lower customer satisfaction. It was also found that in companies with a higher proportion of outsourcing and higher possibility of employment adjustments, workers were less interested in new technologies.