Usually, the time needed for ISO 9001 implementation is the following in terms of timing:
- Companies of up to 10 employees – up to 3 months.
- Up to 50 employees – 3 to 6 months.
- Up to 200 employees – 6 to 10 months.
- More than 200 employees – 10 to 20 months.

Note: These calculations depend mainly on the size of the organization, but you also need to consider the complexity of the processes.

Note: Other factors that can determine the implementation time are:
- Resources assigned for the implementation: personnel and financial resources.
- Experience of the responsible person or team implementing ISO 9001: a consultant will spend less time than if you implement the standard yourself with your own employees.
- Scope of the QMS: the smaller the scope is, the less time will take to implement the standard.

Examples:
- A software company with 10 employees wants to certify the whole organization. For this purpose, hires a consultant who successfully finishes the implementation in 3 months.
- In an organization that manufactures building paints with 100 employees implementing ISO 9001 will take 10 months because processes are more complex and the size of the organization is bigger.