Organisational structure can be defined as the pattern of relationships among positions in the organisation and among members of the organisation. Organisation design and structure is concerned with such elements as:
- The definition and allocation of specific tasks
- The grouping of related tasks into manageable functions, divisions, departments, sections or other units
- The allocation of responsibility within the organisation and to constituent functional units.
The supply function focus primarily on centralised and decentralized purchasing when building up the structures for the organisation. Centralized purchasing encompass grouping of purchasing tasks and specialist functions or services into one serving unit and under unified control. On the other hand decentralized purchasing entail division of purchasing function into sections whereby each section is mandated to control the functions within its scope. Here each department or branch is entirely responsible for its own buying.