work strucuture is termed as mother route of all modules.  
Work structure is the core area where all the setups are 
done.

work structure is a Business entity concept where firstly 
will define a Business group than follows the Business unit,
departments, for Gre/legal entity. And also for reporting 
purpose.

Work Structure (WS) represent the different way in  which 
emp can work within the  enterprise.It provide a framework 
for defining the work assignment of employee.WS represent 
the organisation unit of an enterprices which include dept 
or division, payroll, Job, Position, grade, competence ans 
so on.

Work Structures provide the framework in which you place 
people
They include:
- Enterprise and employer structures such as business 
groups, organizations and legal entities
- Work roles for employees such as Jobs and Positions
- Grade structures with related pay rates
- Payroll Groups with processing calendars

it is the building block of an organization, where an 
employee can work