Expense items represents expenses that have been attributed to an organisation, programme, project or sub-project. Expense items can be any costs associated with the selected asset for example hardware, resources, 3rd party licences etc.
Expense items can be allocated to a particular budget item to track the actual expenditure against the baseline on the budget.
A workflow can also be selected for each expense. When you add the expense item you can select the Standard Expense Item Workflow, or you can add a new workflow for expenses specific to your organisation.