Most contracts initiated by the Department of National Defence are of two types: Temporary help services (THS) and task-based informatics professional services (TBIPS). THS is a common tool to fill in urgent gaps on a short-term basis. It is a maximum of 48 weeks in length and can be extended another 24 weeks only for exceptional requirements. TBIPS fill longer term requirements and are normally one full calendar year with one-year extensions possible provided all parties to the agreement approve. The number of possible year-long extensions are outlined in the solicitation. There are larger contracts using different tools, but those tend to be used for large corporations like Calian or General Dynamics, and those companies hire both employees and contractors to fill military requirements.