Table 1. A summary of generic classification of SaaS Customization.

References	Customization type	Based on
Li, Shi & Li (2009)	GUI , service , process, data and cross-layer	SaaS architecture layers
Tsai & Sun (2013)	GUI, service, process, data and QoS	SaaS architecture layers
	Source code, composition and configuration	Manner of performing
Al-Shardan & Ziani (2015)	GUI, workflow and access control	SaaS architecture layers
Müller et al. (2009)	UI customization, desktop integration and back-end customization	Manner of performing
Kabbedijk & Jansen (2011)	Segment Variability and Tenant-oriented Variability	Tenant and Tenant’s community