The shamrock leaf shape is a symbolic representation of an organization with three types of workforce, having a main body and connected lobes that together form a whole.
The second leaf consists of the contractual fringe and may include individuals who once worked for the organization but now supply services to it.
These individuals operate within broad guidelines set down by the organization but have a high degree of flexibility and discretionary powers.
These workers are sufficiently close enough to the organization to feel a degree of commitment to it, ensuring they maintain a high standard of work.
Handy defines the shamrock organisation as a 'core of essential executives and workers supported by outside contractors and part-time help'.