Availability

Availability is often calculated with the following formula:

This formula takes into account both the time the system is in use (MTBF) and the time it takes to repair (MTTR).

Example: If a machine has an MTBF of 100 hours and an MTTR of 10 hours, availability is calculated as:

This means the machine is available for production 90.91% of the time, while the remaining 9.09% is spent on failures and repairs.

• High Availability: The higher the availability, the more time a system is operational, which is essential for ensuring continuous production processes and achieving business goals. High availability also suggests effective maintenance and a well-designed system.
• Low Availability: Low availability means a system is often unavailable, indicating frequent failures or slow recovery processes. This has direct consequences on productivity and can incur costs.

Availability is an important metric for industrial processes and systems that require continuous operation. Companies often strive for high availability to produce efficiently, minimize costs, and maintain customer satisfaction. It is often monitored in the context of maintenance planning, where both preventive and corrective maintenance are employed to maximize system uptime.

Availability is an essential KPI in maintenance management, providing insight into the operational time of assets and helping to optimise maintenance processes. It supports maintenance scheduling, minimising downtime and improving asset reliability, which is crucial for ensuring continuous production and reducing downtime costs. Availability helps maintenance teams identify bottlenecks, compare performance and prioritise maintenance or replacement investments. By monitoring this metric effectively, organisations can increase reliability, reduce costs and improve operational efficiency.