Introduction

Multi-project management and human resource management are important pillars of business success. Multi-project management is crucial because the share of work that is accomplished within projects has increased steadily during the past 60 years and in some branches virtually all revenues are generated through projects (cf. Kerzner, 2013, pp. 47–63 and 25–27, respectively). As each project demands some resources, proper coordination of projects and resources is vital for a firm. With regard to resources, human resource management is a major factor because the demand for high-skilled workers has increased disproportionately over the last three decades, while skilled workers are a scarce resource (cf. Borjas, 2013, pp. 294–306; Oesch and Rodríguez Menés, 2011; BMWi, 2014).