Eight Quantitative Tools of Quality Control in Manufacturing Process

This article discusses the eight quantitative tools of quality control used in a manufacturing process. It covers topics such as breakdown structure, time estimates, Gantt chart, network diagram, CPM, tradeoff analysis, PERT, and resource management. These tools are essential for organizing and managing work in a manufacturing setting.

Answer 1: The eight quantitative tools of quality control that used in a
manufacturing process are here in below:
 Breakdown structure in case of work.
 Estimates regarding time and precedence relationships.
 Chart regarding Gantt
 Network Diagram
 CPM i.e Critical Path Method
 Tradeoff of time and Cost analysis
 PERT i.e Program Evaluation and Review Technique
 Management of Resources.
1) Break down structure in case of work: It is an approach or way to
work which defines how a particular work to may be divided into
different sub projects, different task and different activities. This work
break down structure is a very good approach to organize the work
and design it .It is one of the most fundament form of organizing the
work. In this structure, the work is divided into different packages and
allocated to a single person or a group of people.
2) Estimates regarding time and precedence relationships: The
series of activities to be performed within a project shall be determined
and the manner in which it is to be performed shall also be
determined. The relationship with each series of activity has to be
clearly identified. Proper care also needs to be taken in order to
estimate the completion time of each activity. The schedule of the
project cost of the resources required and the time required for the
completion of each and individual series of activity.
3) Chart regarding Gantt: It is nothing but a horizontal bar statement,
which depicts the time, required for the entire project. The name Gantt
Chart is named after Henry Gantt, who actually developed the chart in
the year 1910s.The Gantt chart with different color codes make it easy
to analyze and track the performance of the project while it is in
progress.

4) Network Diagram: It is a diagram based on arrows, circles and
nodes. The arrows and circles are drawn in order to create a sequence
of activities within the project. There are two ways in which network
diagram can be drawn like:
Activity on node approach: This is the form in which each activity is
depicted in circles and the circles are connected with arrows.
Activity on arrow approach: This is the form in which each activity
of the project is represented through arrows and the nodes acts as
beginning and ending points.
Diagram on Activity on Node and Activity on Arrow approach:
5) Critical Path Method: It is an algorithm in order to schedule the
activity within the project so that the outcome for the project can be attained
in the fastest and efficient manner .The critical path for the project can be
defined as the path for which the project can take the maximum time or the
longest time for completion. It can be called as a bottleneck path or the
constraint in completing the project. Moreover, the slack in the project can
be defined as the quantity of flexibility that a project has in order to schedule
a particular activity within that project. The algorithm also involves a
computation of four parameters for each activity, which are described here
in below:

 Early Start Time: This is the maximum earliest time in which the
project can be started considering the beginning and ending of each of
the previous activities.
 Early Finish Time: This is the maximum early times in which the project
can be completed. It is calculated as the sum of the maximum early
time and the maximum early completion time.
 Late State Time: This is the maximum late time in which the activity of
the project can be started considering all the previous relationship.
Activity of the project can be started late state but the completion time
for the project has to be in time.
 Late Finish Time: This is the sum of the late state time and the time
required to complete the project.
6) Time tradeoff and Cost Analysis: It is possible sometimes that the
customer needs are not satisfied despite the most efficient schedule than the
extent of the project needs to be changed and additional resources that
needs to be assigned to the project so that the project is completed in a very
fast manner. If the extent of the project is changed than, the team needs to
again evaluate the project using the model critical path method. In addition,
if the additional resources are allocated in order to speed up the project than
the time tradeoff and cost analysis needs to be conducted.
7) Program evaluation and review technique: This is the evaluation
technique in order to address the impact of uncertainties in activity time and
the duration are required to complete the project.
Different schedule can be estimated for activity times like:
 Optimistic Time: This is the minimum time required to complete the
project .Assuming all the previous activity done was better than
expected normally.
 Pessimistic Time: This is the maximum possible time required to
complete the project. Assuming all the previous activity done was at a
very slow pace.
 Most Likely Time: This is the best estimate of the time required to
complete the project assuming that everything is normally preceded.
 Expected Time: This is the best estimate of the time required in order
to complete the task.

8) Management of Resources: The two most commonly used technique for
managing of resources is here in below:
 Resource breakdown structure: It contains the list of staff or employee
required to complete the various activities in the project.
 Levelling of resources: This is an approach in order to reduce the day-
to-day fluctuation of resource requirement within an organization.
It is not possible to use all the above tools of manufacturing process in
service operations. However, some service operations where we can apply at
least three of these tools are ITIL service operations.
Answer 3 (a) Quality costs are the costs incurred in relation to prevent any
issues related to product quality. It does not increase any standard value for
the product instead; it is done in order to meet the customer satisfaction.
(Bragg, 2018)
The four cost of quality are here in described below:
 Prevention Cost: This cost is incurred in order to prevent any quality
issue .This cost is minimal for quality control and is highly advisable.
The prevention cost also reduces the scrap costs, as this cost will lead
to minimal scrap. (Bragg, 2018)
 Appraisal Cost: Same as in the case of prevention cost, appraisal
cost is incurred in order to prevent any quality problem. The test can
be done through a number of ways. The most economical way is
keeping the worker who inspects both incoming and outgoing parts
from the factory so that there is an early detection of any problem.
Other includes like depreciation of test equipment, staff supervision.
(Bragg, 2018)
 Internal Failure Costs: This costs is generally incurred when the
goods which are produced is defective. This cost is generally in the
form of rework goods. In addition, the rework goods cost form part of
this cost. (Bragg, 2018)
 External failure Costs: this cost is generally incurred when defective
goods are produced, but now the cost of product is much more
expensive as it will include warranty cost, legal suite, field service and
other cost promised to bear for the customer.

Answer 3(b): If we designed a better quality product that was easier to
manufacture than both the internal failure and external failure cost would
decrease since the product, which we would produce, will be less defective.
The cost related to appraisal would also decrease due to less audit and
inspection of product but cost relation to prevention would increase since we
want to design a better quality product. (Total Quality Management)
Answer 3(c): If we hired more inspector without changing in any other
aspects of quality than also the defect would would remain unchanged.
However, there is a chance of detecting more defects not all before them
finally reaches to customer. There is an increase in internal failure cost but
the external failure cost will decrease. Appraisal cost will increase as we
have hired more inspector and we have to pay more .But the prevention cost
would remain as it was, as we did not make any changes in it. (Total Quality
Management)
References:
Bragg, S. (2018, February 4). Quality Costs . Retrieved February 21, 2019,
from www.accountingtools.com:
https://www.accountingtools.com/articles/what-are-quality-costs.html
Total Quality Management. (n.d.). Retrieved February 21, 2019, from
www.sba.oakland.edu:
www.sba.oakland.edu/faculty/wharton/.../Questions%20to%20Chapter
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