Multistation series had been rebadged as PS/55 in May. 1987 and had been continued for sale together with MCA PS/55 line.
Following diagram does not contain Multistation series in order to avoid confusion. Check the IBM Multistation Timeline.

					PS/55		| |	PS/55Z or Laptop
1987	MAY	5570-S					| | | | | | | | |
1988	APR	5570-T		5550-S/T			| | | | | | | | |	1988 NOV   5530Z-286
1989	MAY	5570-V0x		5550-V0x			| | | | | | | | |
	NOV					5530-T	| | | | | |	5530Z-SX
1990	MAY	5570-V1x		5550-V1x	5545-T		| | | | | |
	OCT	5580-Y	5560-W	5540-T	5535-S	5530-T	| | | | | | |
1991	MAR						| | | |	5523-S
	MAY			5550-V2			| | | | | |	5510-T	5510-Z
	OCT	5580-W					| | | | | | | |	5530-U	8551-S N51sx  5523SX	5510-S
1992	FEB			5551-W			| | | | | |		5527-U   (N27sx)
	JUN	95XP-486				5530-W	| | | | | | | |	5530-U-SLC/V
	SEP		5560-N				| | | | | | |
	OCT						| | | | |		9552-Y  (C52 486SLC)
1993	JAN						| |		9552-J  (TP720C)
	APR			5551-N/Y			| | | | | |	5530-V2
	OCT	Server 95A	9585	5551-L		PS/55E  5538-Y/Z	| | | | | | |
1994	APR			5551-R	5521Y	5530-L	| | | | | |
					PC 720, 750		| |
1995	JAN			PC720 6860			| | |
	JUN			PC750 6886			| | |