This tool prints the time spent in the kernel before userspace has been reached, the time spent in the initial RAM disk (initrd) before normal system userspace has been reached, and the time normal system userspace took to initialize.
System-analyze blame
This command prints a list of all running units, ordered by the time they took to initialize.
System-analyze critical-chain
This command prints a tree of the time-critical chain of units
System-analyze plot > plot.svg
This command prints an SVG graphic detailing which system services have been started at what time, highlighting the time they spent on initialization.