This document discusses Mean Time Between Failure (MTBF) and Mean Time To Repair (MTTR), which are metrics used to measure equipment reliability. MTBF refers to the average time between failures of a system or machine. It is calculated by dividing the total uptime by the number of failures. MTTR refers to the average time it takes to repair a failure. It is calculated by dividing the total maintenance time by the number of repairs. Both MTBF and MTTR are important for measuring productivity and reducing downtime. Regular maintenance, training, and keeping spare parts can help improve both metrics.

1. BALAKUMAR V
MTBF VS MTTF

2. AGENDA
 What is MTBF?
 MTBF Calculation
 Benefits of MTBF
 What is MTTR?
 MTTR Calculation
 Importance of MTTR
 Benefits of MTTR

3. MTBF – MEAN TIME BETWEEN FAILURE
 It Indicates the expected time between two failures for a repairable
machine or system.
 MTBF =
(No. Of Breakdowns)
(Total Working Time) – ( Total Breakdown Time)
(No. Of Breakdowns)
(Total Uptime)
OR
 It is very important for Total productive Maintenance ( TPM)
implementation which is one of the Most Popular Lean Manufacturing Tool.

4. MTBF CALCULATION
 Three Similar machines starting to function properly at 0 Hours are working until all of them fail.
 The First machine failed at 120 Hours, The Second failed at 140 Hours and the third failed at 150 Hours.
 The MTBF = (Total Uptime) / (No. of breakdowns)
 = [(120+140+150)] / 3
 = 136.667 Hours
 The MTBF is the average of the three failures, which is 136.667 Hours.
 It can be calculated as the arithmetic mean between the failures of equipment.
 In Other Words, It is the average duration between the failure of equipment.
 This Value 136.667 means that a failure in the system occurs every 136.667 hours and it generates losses to the
company.
 The Opportunity is to increase the duration between two breakdowns.
 In Other Words, the MTBF is the timing from one failure to another for repairable equipment.

5. How Can I Improve my MTBF?
 We Can Improve it by Regular maintenance of machines.
 By Implementing small Kaizen Activity for the Equipment.
 Make an Equipment breakdown history book and take a strong Preventing action
on it so this breakdown will not repeat in the future.
Benefits of MTBF:
 It is a Basic Indicator to Predict the reliability of a machine.
 If the MTBF has increased after a preventive maintenance activity then this indicates a clear
improvement in the quality of your processes.
 It is very useful for implementing Lean Manufacturing Culture in the Factory.
 The MTBF increases will Show that your maintenance or verification methods are going good.
 It Should be used to elaborate on the Company’s knowledge about Processes.
 It Reduces Losses in Productivity and also improves the Quality of the Product.

6. MTTR
 It is the Average Time Required to analyze and solve the problem and it tells us how
well an organization can respond to machine failure and repair it.
 In Other Words, failed equipment returns to normal operating conditions or the mean
timing duration between the equipment failure and returns to operation. It is a Basic
technical indicator related to the maintainability of the machine and repairable parts.
 It represents the average duration required to repair a failed component.
 In Other Words, how long the machine is out of production.
 This Includes notification timing, analysis timing, Fixing timing, Waiting, Reassembly
timing, alignment timing, Calibration timing, testing timing Etc.
 The Formula of MTTR = Total Maintenance Time / Number of repairs.
 It is also called as the meantime to recovery.

7. MTTR CALCULATION
 A Machine Should operate correctly for 20 Hours. During this Period, 6 Failures occurred. The sum of all failure
duration is 90 Minutes.
 The MTTR = (Total Maintenance time) / (No. of Repairs)
 = 90 / 6
 = 15 Hours
IMPORTANCE OF MTTR
 It has a remarkable effect on the organization’s profit.
 Long MTTR means loss of productivity and sometimes, an organization can miss an order or it can impact business
relationships.
 To reduce the impact of MTTR, Organizations should have their own maintenance teams and hold critical spare
parts onsite or run parallel production times.

8. How Can I Improve my MTTR?
 We Can Improve it by Teamwork.
 Implement and follow the troubleshooting manual concept or breakdown history concept.
 By Providing training on quick repair and motivate people.
 Maintaining 5S.
 Follow the Standardized Operation Procedure.
 Keep the Critical Spare in Stock
Benefits of MTTR:
 It Indicates the efficiency and Productivity of the equipment and it has reduced after the preventive Maintenance of the
Machine.
 By Reducing Mean Time to Repair we can improve the efficiency and productivity of the machine.
 Lower MTTR indicates that your company has an immediate action plan to overcome failure.
 It Should be used to elaborate on the company’s knowledge about how strong the action plan against the machine
failure.
 It reduces losses and also improves productivity and Quality of the Product.
 It is very useful for implementing Lean Manufacturing Culture in the Factory.

9. THANK YOU