“Integration is believed to occur through two mechanisms: flexibility and permeability. Flexibility refers to the malleability of the boundary between two or more role/domains-its ability to expand or contract-to accommodate the demands of one domain or another (Ashforth et al., 2000; Clark, 2000; Hall & Richter, 1988). Permeability involves the extent to which a boundary allows psychological or behavioral aspects of one role or domain to enter another (Ashforth et al., 2000; Clark, 2000; Hall & Richter, 1988; Pleck, 1977). When two or more roles or domains are flexible and permeable, they are said to be blended (Clark, 2000) or integrated (Ashforth et al., 2000).”
“[I]ntegration is denoted by roles that are weakly differentiated (low contrast), are not tied to specific places and times (flexible boundary), and allow cross-role interruptions (permeable boundary)” (p. 479). (Ashforth, Kreiner, & Fugate, 2000).
Nippert-Eng (1996) argues that when home and work are fully integrated, “no distinction exists between what belongs to ‘home’ or ‘work’ and when and where they are engaged” (p. 5). (Nippert-Eng,1996)

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