“…For example, Ellinger et al (2008) used variables such as increase in personnel efficiency through the years and increase in market share, whereas Wang et al (2010) used operational variables such as customer service, delivery speed, and delivery reliability. Lai (2004) has used variables related to services such as assisting customers to solve problems, efforts shown in emergency cases, and assessing customer complaints, while Mothilal et al (2012) and Liu & Lyons (2011) used financial and operational performance variables. Karia & Wong (2013) used variables which are directly related with logistics services such as better services, greater percentage of on-time and accurate delivery, quick responses, more unique solution, more satisfied with the service level, more additional service, lower facility cost, lower distribution cost.…”