This dissertation titled “Implementation of Preventive Maintenance Schedule on Main Assembly 1 Machine in Spare Part Manufacturer Company” prepared and submitted by Nabila Aulia Asdin in partial fulfillment of the requirements for Bachelor Degree in Engineering Faculty has been reviewed and found to have fulfilled the requirements for a thesis suitable for assessment. I declare that this thesis entitled "Implementation of Preventive Maintenance Scheduling on Main Assembly 1 Machine in Spare Part Manufacturer Company" is to the best of my knowledge and belief an original piece of work that has not been submitted, in whole or in part, to any other university to get a degree. NAA is an automotive manufacturing company that produces two types of vehicle spare parts: alternator and rotor assembly.
By implementing preventive maintenance planning, machine reliability can be increased by 21.65% and maintenance cost can be reduced by 14.56% or IDR. Thank you for the guidance and knowledge from the first day I studied at this university until today. Thank you for making me feel happy all the time, for always reminding me to appreciate everything I have.
Purnama Sahid Antasara, Aldino Fajri, Prananda Jalu, Fikri Aswan and Marsha Sortatiur Natahania, thank you for helping me and boosting my spirit to complete my thesis. For all the wonderful people in my life who cannot be named one by one, but always give me motivation, support and colorful life.
INTRODUCTION
- Problem Background
- Problem Statement
- Objectives
- Scope and Limitation
- Assumptions
- Research Outline
Downtime that occurred on the rotor assembly line is because the average age of the machine is more than 10 years. The policy of the company's management prefers to do machine maintenance than to replace the old machines with the new ones. Rotor assembly line has 32 machines, one of them is main assembly 1 machine which affects the highest down time in rotor assembly line.
The main assembly 1 is a machine used to assemble several parts such as the rear field coil of the front post, shaft and slip rings. Currently, the company uses breakdown maintenance, which is corrective maintenance in handling the machine that maintenance is done after the breakdown has occurred, where the maintenance of a component waits until the component breaks down and is then repaired or replaced with a new component. The importance of preventive maintenance is to improve machine performance to avoid any unplanned maintenance activities and to avoid larger and costly repairs to the bottom line where maintenance tasks are performed routinely.
Having scheduled preventive maintenance can keep the machine up and running because machine performance is an important aspect to consider in the production process. This chapter consists of problem background, problem statements as the things to be solved, objectives to be achieved in this research, scope as limitation, assumption and research outline of the study.
LITERATURE STUDY
- Maintenance
- Reliability
- Failure Rate
- Failure Distribution
- The Normal Distribution
- The Exponential Distribution
- The Weibull Distribution
- The Lognormal Distribution
- Statistical Approach
- Probability Density Function
- Cumulative Density Function
- Reliability Function
- Maintenance Interval Time
Engine spare parts were assumed to be available when needed during normal or emergency situations.
RESEARCH METHODOLOGY
Initial Observation
Problem Identification
Literature Study
Data Collection
Data Calculation and Analysis
Conclusion and Recommendation
Detailed Research Framework
DATA COLLECTION AND ANALYSIS
Data Collection
- Current Condition Analysis
- Identify Production Area Downtime
- Identify Machine Downtime
- Identify Component Machine Downtime
- Component Machine Failure Data
26 Table 4.1 explains the comparison between the monthly planned production quantity and the actual production quantity in the year 2016. Table 4.1 shows that the total of the planned production quantity and the actual production quantity differ. For the details, Appendix 2 shows the standstill data of each machine in the rotor assembly line.
The table shows that the most common critical parts that caused machine failures were the chuck holder shaft, pin B, and chuck holder slide ring. The chuck holder shaft, B-pin and chuck holder slip ring have the highest number which becomes the main cause of machine failure. In the last six months of 2016, the chuck holder shaft failed 24 times with a total time of 33 hours or 1980 minutes.
Chuck holder slip ring breaks down 8 times with total time 960 minutes while B-Pin breaks 8 times with total time 8.75 hours or 525 minutes. Based on the data, the critical component machine will be focused on chuck holder shaft, chuck holder slip ring and b-pin. Sensor of drill head holder shaft must replace the broken sensor with the new sensor.
The failure that occurred in the chuck holder slip ring was that the sensor was not detected because it was contaminated with dust, but it was not detected. Part component machine failure data over the past six months is needed to estimate the time to perform preventive maintenance. From the previous section, main assembly machine 1 has the highest downtime on the rotor assembly line.
The three components of Main Assembly 1 that have the highest downtime are the cap holder shaft, chuck holder slip ring, and needle b. NAA, component machine failure data is differentiated based on several types of maintenance process, which are setting for chuck holder shaft, cleaning for b-pin, repair for chuck holder shaft and holder slip ring and July to December 2016 chuck carrier shaft replacement.
Data Calculation
- Time to Repair (TTR), Time to Failure (TTF) and Time between
- Distribution Identification
- Maintenance Cost
- Component Machine Maintenance Interval
37 Below is an example of a TTR and TBF chuck shaft holder for adjustment. Below is an example of a TTR and TBF shaft holding chucks for repair. Below is an example of a TTR and TTF shaft holder chuck for replacement activity.
Below is the example of TTR and TBF of chuck holder slip ring for repair activity. For example, the repair activity of the tensioner shaft is matched with all the failure distribution. For example, the set activity of the tensioner shaft is matched with all the failure distribution.
Data Analysis and Improvement
- Current Reliability
- Interval Time of Maintenance
- Proposed Preventive Maintenance Schedule
- Component Machine Reliability Comparison after Improvement
- Maintenance Cost Comparison
CONCLUSION AND RECOMMENDATION
Conclusion
The main assembly 1 is a machine used to assemble several parts such as the rear field coil of the front post, shaft and slip rings. During the last six months in 2016, there are several components that cause the highest downtime. The most critical components that enabled the highest machine downtime are the cap carrier shaft, cap carrier slip ring, and needle b.
The reliability of the assembly machine of the chuck holder shaft, chuck holder slip ring and b-pin is 50% respectively. Then the company successfully achieved the machine reliability target of 70% with MTTF and MTBF of each component or 456.67 hours, 200 hours and 720 hours.
Recommendation
Machine Downtime from July-December 2016
Picture
Component Failure Data
Goodness of Fit Test Result
Histogram
Proposed Preventive Maintenance Schedule from January to
