Quality control is a process used to ensure a certain level of quality in products and services. It involves testing products and services to ensure they meet specific requirements. Quality control can occur when raw materials are received, during production, and after production by inspecting finished products before delivery to customers. Some common quality control methods include checking food for taste, inspecting clothing for proper sewing, and following up on services. The overall goal is to deliver dependable, satisfactory, and safe products and services.
2. What is Quality Control?
Quality control is a process that is used to ensure a certain level of quality
in a product or service.
It might include whatever actions a business deems necessary to provide
for the control and verification of certain characteristics of a product or
service.
Most often, it involves thoroughly examining and testing the quality of
products or the results of services.
The basic goal of this process is to ensure that the products or services
that are provided meet specific requirements and characteristics, such as
being dependable, satisfactory, safe and fiscally sound.
3. Basic examples of Quality Control:
Manufacturers of food products often have employees who test the
finished products for taste and other qualities.
Clothing manufacturers have workers inspect garments to ensure that they
are properly sewn.
Service-oriented companies often have representatives who observe the
services being performed or who do follow-up checks to ensure that
everything was done properly.
4. What does Quality Control occur?
When raw materials are received prior to entering production.
Whilst products are going through the production process.
When products are finished - inspection or testing takes place before
products are dispatched to customers.
Evaluating people. (Applicable with service-oriented companies.)
5. 7 Basic Tools of Quality
1. Check sheet - is a form used to collect data in real time at the location where the data
are generated. The data it captures can be quantitative or qualitative. When the
information is quantitative, the check sheet is sometimes called a tally sheet.
2. Control chart - also known as Shewhart charts or process behavior charts, in statistical
process control are tools used to determine if a manufacturing or business process is in
a state of statistical control.
3. Histogram - is a graphical representation showing a visual impression of the
distribution of data.
4. Ishikawa Diagram - Common uses of the Ishikawa diagram are product design and
quality defect prevention, to identify potential factors causing an overall effect. Each
cause or reason for imperfection is a source of variation. Causes are usually grouped
into major categories to identify these sources of variation.
5. Pareto Chart - is a type of chart that contains both bars and a line graph, where
individual values are represented in descending order by bars, and the cumulative total
is represented by the line.
6. Scatter diagram - is a type of mathematical diagram using Cartesian coordinates to
display values for two variables for a set of data.
7. Flow chart - is a type of diagram that represents an algorithm or process, showing the
steps as boxes of various kinds, and their order by connecting them with arrows
6. Some problems concerning Quality
Control:
The inspection process does not add any "value". If there were any guarantees that no
defective output would be produced, then there would be no need for an inspection
process in the first place.
Inspection is costly, in terms of both tangible and intangible costs. For example,
materials, labor, time, employee morale, customer goodwill, lost sales.
It is sometimes done too late in the production process. This often results in defective or
non-acceptable goods actually being received by the customer.
It is usually done by the wrong people - e.g. by a separate "quality control inspection
team" rather than by the workers themselves Inspection is often not compatible with
more modern production techniques (e.g. "Just in Time Manufacturing") which do not
allow time for much (if any) inspection.
There is often disagreement as to what constitutes a "quality product". For example, to
meet quotas, inspectors may approve goods that don't meet 100% conformance, giving
the message to workers that it doesn't matter if their work is a bit sloppy. Or one quality
control inspector may follow different procedures from another, or use different
measurements
7. Difference between
Quality Control & Quality Assurance
Though the two are similar, but there are some basic differences. Quality
control is concerned with examining the product or service the end result ‐
and quality assurance is concerned with examining the process that leads
to the end result.
A company would use quality assurance to ensure that a product is
manufactured in the right way, thereby reducing or eliminating potential
problems with the quality of the final product.
8. "Inspection with the aim of finding the bad ones and throwing them out is
too late, ineffective, costly. Quality comes not from inspection but from
improvement of the process." - W. Edwards Deming