Reliability Analysis and Improvement Project - Engineering Mechanics

This project analyzes a manufacturing process using the Critical Path Method (CPM) to identify bottlenecks and calculate takt time, revealing a constraint that needs addressing. It develops leading and lagging indicators based on the CPM, suggesting potential areas for lagging operations to optimize time. The project proposes strategies to improve metrics by reducing the time taken in critical path elements, particularly OP-4/2 and OP 2, and further suggests reducing time in other operations as an alternative. It outlines the role of a Reliability Engineer in managing risks, ensuring asset reliability, and addressing failures, including data analysis techniques and failure reporting. The project calculates the initial system reliability based on individual component reliabilities and explores methods to increase it through targeted spending on component improvement and redundancy. Finally, it analyzes failure data for machines OP-5 and OP-8, determining the distribution and calculating reliability using exponential formulas, and estimates reliability for OP-7 using mean estimates.

Answer-1
The problem using the Critical Path Method lies in the fact that the time taken as per CPM
elaborated in the diagram is 141 seconds wherein the path followed is 7-5-4/2-1 while the
takt time established is 101.12 seconds. Accordingly, there is a bottleneck constraint which
needs to be removed in order to match the takt. Further, takt has been computed by using
the formula: No of units required to be produced of a particular product/ Time available to
produce those units. On the basis of the above formula, the takt time has been computed
as 101.12 seconds.
Answer-2
The leading and lagging indicators have been developed based on critical path method
wherein the following factors have been computed Early Start Time, Early Finish Time, Late
Start Time and Late Finish Time. On the basis of same, the work done under OP 3, OP 6, OP
5 and OP 2 can be lagged as there is excess time available for same. For detailed
computation refer excel and diagram.
Answer-3
The metrics can be improved by reducing the critical path method especially the critical
elements in the chain i.e OP-4/2 and OP 2 where in the time taken shall be reduced in order
to be in alignment with takt as other path developed have time frame less than takt. Thus,
the most appropriate strategy for the company shall be to reduce the time taken for OP-4/2
and OP 2. Further, as alternative course of action time taken by OP 5, OP 1 and OP 7 shall
also be reduced to reduce the stress on other two machineries.
The above strategy if implemented may help the company to reduce the time taken or CPM
to be in align with the takt time and meet the production requirement.
Answer-4
The main role of Reliability Engineer is the identification and managing the risks that could
easily affect the plant and the business operations .To manage the risk it can be classified
into three categories like elimination of loss, Management of Risk and Life Cycle Asset
Management. The loss elimination is to track the losses arising due to production and in
maintaining the high maintenance cost assets and find ways in order to reduce such high
costs. The main role is to ensure and maintain the assets through its entire life cycle .To
participate in the implementation and design of the equipment and to perform the testing
process of the assets and the equipment at reasonable intervals, which includes factory and
site testing which lead to functional working of all machines together without any
interruption. To keep effort in order to ensure the reliability of the equipment process,
utilities and the safety procedure and system. To draft a solution for the repetitive failure of
some major major problems that generally affect the plant operations adversely .Some of
the problems which may include like capacity, quality, cost or compliance issues. To carry
out this responsibility the reliability engineer should follow or include a) Data analysis
technique process that may or can include process related to statistical control b) prediction
related to reliability modeling c) methodology through six sigma analysis d) Weibull Tree

analysis. The analysis of the failure through the deep insight into it and the causes behind it.
The reporting of the failure and the corrective action need to be taken in order to prevent
any other failure from cropping. It is also very necessary to provide the support to the
technical people engaged in the production process and the maintenance and management
process. In order to take the decision regarding the buy/sell or repair/re design or
repair/replace one should apply the value analysis tool in order to take the decision.
Answer-5
The reliability of the system has been computed considering that the system is serial and
each machinery shall follow the other. The reliability has been computed by multiplying the
reliability of each individual component. Accordingly, the reliability computed stands at
0.06.
Under the first condition of the question of increasing reliability by 0.1 by spending 1,00,000
$, the same has been spend to increase the reliability of 1, 3 4, 5, 6 and 8th machinery. The
computed reliability stands at 0.24.
Under the second condition of the question, the redundancy has been done for OP 3 and OP
6 as the reliability for other factors are greater than 0.5. Accordingly, the reliability
computed stands at 0.09.
Answer-6
For computing the reliability of OP-5 Lambda is computed. The computation has been done
based on the following formula:
Lambda= Failure order/ Time to Failure
Further, reliability has been computed by using the exponential formula which is presented
as under:
Reliability = Exponential (- Lambda* 725)
The data is following a bath tub curve as the machine is new and the failure are decreasing
with passage of time and shall become still post that it shall increase.
The distribution is normal.
Answer-7
For computing the reliability of OP-8 Lambda is computed. The computation has been done
based on the following formula:
Lambda= Failure order/ Time to Failure
Further, reliability has been computed by using the exponential formula which is presented
as under:
Reliability = Exponential (- Lambda* 888835)

Answer-8
For computing the reliability of OP-7 Mean estimate is computed. The computation has
been done based on the following formula:
Mean estimate is computed by drawing horizontal line that goes through t=0 and t=100%.
Accordingly, the mean estimate has been computed at 96.
Further, Lambda is computed as 1/ mean estimate
Reliability is computed at 1 almost