This thesis entitled "Implementation of a preventive maintenance system in automotive machinery assembly to increase machine reliability in a toy manufacturing company", prepared and submitted by Valentina Novita Bere in partial fulfillment of the requirements for the degree of Bachelor's degree at the Faculty of Engineering, has been reviewed and was found to have met the requirements for a thesis suitable for research. I declare that this thesis, entitled “Implementation of a preventive maintenance system in toy car machine assembly to increase machine reliability in a toy manufacturing company”, is, to the best of my knowledge and belief, an original piece of work that has not been submitted. completely or partially to another university to obtain a degree. During the production process, machine performance can be derived from machine downtime data.
The calculation of each component is based on the failure distribution that fits the failure data of the components. Especially my family, my beloved daddy, my supermom, my beloved brother, my dear sister Thessa and my Eugidro, who always prayed, motivated and cheered me up during the most difficult time of completing this research. Andira as head of the Industrial Technology course, who had given me the opportunity to complete this research.
Breakdown machine: the condition when the machine cannot operate due to component failure. TTR: Time to repair is the time from start of machine or component repair to completion.
Problem Background
Based on the downtime report for this auto machine for the last six months, the percentage of downtime was 55% of the total production period. When process production in this line stops, it will result in low achievement of targeted output. If that day's output is not achieved due to machine breakdown, there is overtime to meet the production target that had to be achieved.
To solve this problem, the machine must have a preventive plan to avoid machine downtime during production time and also to increase machine reliability.
Problem Statement
In this research, formulas based on the type of failure distribution are used to calculate the MTTF. Here are the formulas used to calculate the MTTF of each component based on the type of failure distribution. In this research, MTTR is calculated based on time-to-repair data for each machine or component.
Once all the calculations are done, preventive maintenance can be performed based on the failure time interval of the components. The formula used to calculate the data based on the error distribution types is provided in this chapter. Then, the next step was to calculate the MTTF and reliability of each component based on the type of data error distribution.
The data calculation is started by calculating TTF and TTR based on the time loss of each component. After that, the reliability of each component is also calculated based on the distribution type. Finally, scheduling the preventive maintenance based on the mean time of failure chosen to achieve the target reliability proposed.
30 These components will be analyzed based on the time loss and data calculation to develop the preventive maintenance system for these components. Fault occurrence in Automachine 2 based on each component is shown in the following table. Based on the result above, here is the example of TTF calculation to get the TTF number.
The MTTF of the vacuum is calculated based on the TTF data that was calculated earlier. Springer's MTTF will be calculated using the same software based on a lognormal distribution. Based on the time to repair calculated in the previous subsection, at this stage the data is entered into the statistical software to calculate the MTTR of each component.
A component replacement interval calculation is performed to know when a component should be replaced based on the reliability target to be achieved. This calculation is based on the type of distribution that fits the sensor error data. Planning the time to perform preventive maintenance is based on the interval time for component replacement with an average reliability of 80%.
The preventive maintenance for each component for the next months will be performed based on the schedule above.
Problem Objective
Scope
Assumption
Research Outline
Definition of Maintenance
Types of Maintenance
- Preventive Maintenance
- Corrective Maintenance or Breakdown Maintenance
Failure Distribution
- Weibull Distribution
- Normal Distribution
- Lognormal Distribution
- Exponential Distribution
Failure Rate or Hazard Rate Function
Probability Density Function
Reliability Function
Mean Time to Failure
Mean Time to Repair
Determine Preventive Maintenance Interval
Theoretical Framework
- Initial observation
- Problem Identification
- Literature Study
- Data collection
- Data Analysis
- Conclusion and Recommendation
In this step, the current state was observed by collecting all the information about the production process in the toy assembly area. Data to be analyzed in this research are down time data of area TA, data of machine in area TA, data of component price, data of maintenance cost and also capacity of auto machine in area TA. In this phase, the problems have been found through the data analysis of the current system.
The next step is to determine the research objectives to be achieved by this research. Based on the initial observation, there were several machines in the TA area, and this study only focused on the highest failure rate of machines belonging to the Auto machine. There are also several assumptions in this observation to ensure that the entire process of this observation can be done properly.
Downtime data was needed to analyze machine failure rate and duration between failures in order to estimate machine failure time. The machine component was also needed to classify the schedule based on the priority of the component's function and the price. The data for the components needed in this research were, the price of the component, the function of the component and the average time to repair the component which are standardized by the company.
In this step, the analysis of the machine downtime data and the search for the most common components of the machine failures were carried out. In addition, the calculation of TTF, TTR, MTTF, MTTR, machine reliability and maintenance cost has been explained in this chapter. After calculating the TTF of each component, all TTF data were analyzed using statistical software to fit the data to a type of error distribution.
Maintenance costs in the current condition and proposed condition were also calculated in this step. The comparison of current and proposed condition based on the reliability calculation, maintenance cost calculation and time to repair in current and proposed calculation was also done in this step. The conclusion of this research based on the calculation in the previous chapter is summarized in this step.
Research Framework
- Current Condition Analysis
- Identify Component failure
- Component Failure data
- Downtime and Time to Failure of Components
- TTF and TTR calculation of Cylinder
- TTF and TTR Calculation of Vacuum
- TTF and TTR Calculation of Sensor
- TTF and TTR Calculation of Join Leg
- TTF and TTR Calculation of Pallet
- TTR and TTF Calculation of Springer
- MTTF and Reliability of Component
- Cylinder
- Vacuum
- Sensor
- Joint Leg
- Pallet
- Springer
- MTTR Calculation
- Calculation of Maintenance Cost
- Corrective Maintenance Cost (Cf)
- Preventive Maintenance Cost (Cp)
- Component Replacement Interval
- Cylinder
- Vacuum
- Sensor
- Joint Leg
- Pallet
- Springer
- Analysis Current and Proposed Condition
- MTTR Comparison
- Reliability Comparison
- Cost Comparison
- Scheduling Preventive Maintenance for the Next 3 Months (Jan- March 2017)
All data are analyzed based on the method of reliability that has been explained in chapter two. The correct preventive maintenance schedule created from the result of calculation and analyst data is also available in this chapter.
Conclusions
Based on the outage report that occurred in Auto Machine 2, there are 6 components that have a high number of outages and failures in the last six months from January 2016 to July 2016. These critical components that occurred frequently in Auto Machine 2 , are the cylinder, vacuum, sensor, articulated leg, pallet and spring. To determine the preventive maintenance schedule, some calculations need to be done, such as calculating the TTF and TTR of each component, calculating the MTTF and MTTR of the component, and calculating the reliability of each component based on the MTTF of each component.
The entire component can meet the reliability target set by the company that all components must have 80% reliability. On the other hand, by implementing the preventive maintenance in machine Auto 2, the cost of maintenance is also reduced compared to the current state. By implanting the preventive maintenance, waiting time and production loss can be eliminated from the maintenance costs.
Recommendation
