Process Capability - Revision history

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User at 18:46, 11 November 2021

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 ===See Also===
-*[[Process Analysis]]
+Process Capability is a statistical measure of a process's ability to produce output within specified limits. It relates to the inherent variability of a process under statistical control and compares that variability to the allowed tolerance or specifications. This measure is vital in manufacturing, quality control, and Six Sigma projects to determine how well a process can meet customer requirements. Understanding process capability helps organizations optimize their processes, reduce waste, and improve product quality and consistency.
-*[[Process Model]]
 ===References===
 <references/>

@@ Line 55: / Line 55: @@
 ===See Also===
 *[[Process Analysis]]
 *[[Process Model]]
 ===References===
 <references/>

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-'''Process Capability(C<sub>p</sub>)''' is a measurable property of a [[Process|process]] to the specification, expressed as a process capability index (e.g., C<sub>pk</sub> or C<sub>pm</sub>) or as a process performance index (e.g., P<sub>pk</sub> or P<sub>pm</sub>). The output of this measurement is often illustrated by a histogram and calculations that predict how many parts will be produced out of specification (OOS). Two parts of process capability are: 1) measure the variability of the output of a process, and 2) compare that variability with a proposed specification or product tolerance.<ref>Definition - What Does Process Capability Mean? [https://en.wikipedia.org/wiki/Process_capability Wikipedia]</ref>
+'''Process Capability(C<sub>p</sub>)''' is a measurable property of a process to the specification expressed as a process capability index (e.g., C<sub>pk</sub> or C<sub>pm</sub>) or as a process performance index (e.g., P<sub>pk</sub> or P<sub>pm</sub>). The output of this measurement is often illustrated by a histogram and calculations that predict how many parts will be produced out of specification (OOS). Two parts of process capability are 1) measure the variability of the output of a process, and 2) compare that variability with a proposed specification or product tolerance.<ref>Definition - What Does Process Capability Mean? [https://en.wikipedia.org/wiki/Process_capability Wikipedia]</ref>
 '''Process Capability Index (C<sub>pk</sub>)<ref>Process Capability Index (C<sub>pk</sub>) [https://www.whatissixsigma.net/process-capability-index-cpk/ What is Six Sigma]</ref>'''<br />
-Process capability index (C<sub>pk</sub>) is a statistical tool, to measure the ability of a process to produce output within customer’s specification limits. In simple words, it measures producer’s capability to produce a product within customer’s tolerance range. C<sub>pk</sub> is used to estimate how close you are to a given target and how consistent you are to around your average performance. C<sub>pk</sub> gives you the best-case scenario for the existing process. It can also estimate future process performance, assuming performance is consistent over time. C<sub>pk</sub> is a standard index to state the capability of one process, the higher the C<sub>pk</sub> value the better the process is. For instance, Machine 1 has a C<sub>pk</sub> of 1.7 and machine 2 has a C<sub>pk</sub> of 1.1. From the C<sub>pk</sub> value, one can derive that Machine 1 is better than 2. Since C<sub>pk</sub> uses specification limits and parts variation (sigma), we can also arrive at the yield processed and losses from the machine.
+Process capability index (C<sub>pk</sub>) is a statistical tool, to measure the ability of a process to produce output within a customer’s specification limits. In simple words, it measures the producer’s capability to produce a product within the customer’s tolerance range. C<sub>pk</sub> is used to estimate how close you are to a given target and how consistent you are around your average performance. C<sub>pk</sub> gives you the best-case scenario for the existing process. It can also estimate future process performance, assuming performance is consistent over time. C<sub>pk</sub> is a standard index to state the capability of one process, the higher the C<sub>pk</sub> value the better the process is. For instance, Machine 1 has a C<sub>pk</sub> of 1.7 and machine 2 has a C<sub>pk</sub> of 1.1. From the C<sub>pk</sub> value, one can derive that Machine 1 is better than 2. Since C<sub>pk</sub> uses specification limits and parts variation (sigma), we can also arrive at the yield processed and losses from the machine.
 Cpk is a standard index to state the capability of one process, the higher the Cpk value the better the process is. For instance, Machine 1 has a Cpk of 1.7 and machine 2 has a Cpk of 1.1. From the Cpk value, one can derive that Machine 1 is better than 2. Since Cpk uses specification limits and parts variation (sigma), we can also arrive at the yield processed and losses from the machine.
@@ Line 54: / Line 54: @@
 ===See Also===
-[[Process Analysis]]<br />
+*[[Process Analysis]]
-[[Process Analytics]]<br />
+*[[Process Analytics]]
-[[Process Architecture]]<br />
+*[[Process Architecture]]
-[[Process]]<br />
+*[[Process Capability Assessment Model (PCAT)]]
-[[Process Capability Assessment Model (PCAT)]]<br />
+*[[Process Classification Framework (PCF)]]
-[[Process Classification Framework (PCF)]]<br />
+*[[Process Hierarchy Diagram]]
-[[Process Control]]<br />
+*[[Process Mapping]]
-[[Process Decision Program Chart]]<br />
+*[[Process Mining]]
-[[Process Hierarchy Diagram]]<br />
+*[[Process Model]]
-[[Process Integration]]<br />
+*[[Process Optimization]]
 ===References===
 <references/>

@@ Line 54: / Line 54: @@
 ===See Also===
-[[Process Analysis]]V
+[[Process Analysis]]<br />
 [[Process Analytics]]<br />
 [[Process Architecture]]<br />

← Older revision		Revision as of 19:46, 11 November 2021
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	Through examination of the reports, we can determine that our example process is in a state of statistical control. All the data points fall well within the specification limits with a normal distribution. A process where almost all the measurements fall inside the specification limits is deemed a capable process. Process capability studies are valuable tools when used properly. As previously mentioned the information gained is generally used to reduce waste and improve product quality. In addition, by knowing your process capabilities, the design team can work with manufacturing to improve product quality, and processes that are “not in control” may be targeted for improvement. During a typical Kaizen event or other quality improvement initiatives, Process Capability is calculated at the start and end of the study to measure the level of improvement achieved. Accurate knowledge of process capability enables management to make decisions regarding where to apply available resources based on data.		Through examination of the reports, we can determine that our example process is in a state of statistical control. All the data points fall well within the specification limits with a normal distribution. A process where almost all the measurements fall inside the specification limits is deemed a capable process. Process capability studies are valuable tools when used properly. As previously mentioned the information gained is generally used to reduce waste and improve product quality. In addition, by knowing your process capabilities, the design team can work with manufacturing to improve product quality, and processes that are “not in control” may be targeted for improvement. During a typical Kaizen event or other quality improvement initiatives, Process Capability is calculated at the start and end of the study to measure the level of improvement achieved. Accurate knowledge of process capability enables management to make decisions regarding where to apply available resources based on data.
		+
		+
		+	===See Also===
		+	[[Process Analysis]]V
		+	[[Process Analytics]]<br />
		+	[[Process Architecture]]<br />
		+	[[Process]]<br />
		+	[[Process Capability Assessment Model (PCAT)]]<br />
		+	[[Process Classification Framework (PCF)]]<br />
		+	[[Process Control]]<br />
		+	[[Process Decision Program Chart]]<br />
		+	[[Process Hierarchy Diagram]]<br />
		+	[[Process Integration]]<br />
		+	[[Process Mapping]]<br />
		+	[[Process Mining]]<br />
		+	[[Process Model]]<br />
		+	[[Process Optimization]]<br />
		+	[[Mainframe]]<br />
		+	[[Operating System (OS)]]<br />
		+	[[Central Processing Unit (CPU)]]<br />
		+	[[Computer Networking]]<br />
		+	[[Computer Program]]<br />
		+	[[Computer-Aided Process Planning (CAPP)]]<br />
		+	[[Business Process]]
		+
		+
		+	===References===
		+	<references/>

← Older revision		Revision as of 19:41, 11 November 2021
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−	'''Process Capability Index (C<sub>pk</sub>)'''<br />	+	'''Process Capability Index (C<sub>pk</sub>)<ref>Process Capability Index (C<sub>pk</sub>) [https://www.whatissixsigma.net/process-capability-index-cpk/ What is Six Sigma]</ref>'''<br />
	Process capability index (C<sub>pk</sub>) is a statistical tool, to measure the ability of a process to produce output within customer’s specification limits. In simple words, it measures producer’s capability to produce a product within customer’s tolerance range. C<sub>pk</sub> is used to estimate how close you are to a given target and how consistent you are to around your average performance. C<sub>pk</sub> gives you the best-case scenario for the existing process. It can also estimate future process performance, assuming performance is consistent over time. C<sub>pk</sub> is a standard index to state the capability of one process, the higher the C<sub>pk</sub> value the better the process is. For instance, Machine 1 has a C<sub>pk</sub> of 1.7 and machine 2 has a C<sub>pk</sub> of 1.1. From the C<sub>pk</sub> value, one can derive that Machine 1 is better than 2. Since C<sub>pk</sub> uses specification limits and parts variation (sigma), we can also arrive at the yield processed and losses from the machine.		Process capability index (C<sub>pk</sub>) is a statistical tool, to measure the ability of a process to produce output within customer’s specification limits. In simple words, it measures producer’s capability to produce a product within customer’s tolerance range. C<sub>pk</sub> is used to estimate how close you are to a given target and how consistent you are to around your average performance. C<sub>pk</sub> gives you the best-case scenario for the existing process. It can also estimate future process performance, assuming performance is consistent over time. C<sub>pk</sub> is a standard index to state the capability of one process, the higher the C<sub>pk</sub> value the better the process is. For instance, Machine 1 has a C<sub>pk</sub> of 1.7 and machine 2 has a C<sub>pk</sub> of 1.1. From the C<sub>pk</sub> value, one can derive that Machine 1 is better than 2. Since C<sub>pk</sub> uses specification limits and parts variation (sigma), we can also arrive at the yield processed and losses from the machine.
		+
		+	Cpk is a standard index to state the capability of one process, the higher the Cpk value the better the process is. For instance, Machine 1 has a Cpk of 1.7 and machine 2 has a Cpk of 1.1. From the Cpk value, one can derive that Machine 1 is better than 2. Since Cpk uses specification limits and parts variation (sigma), we can also arrive at the yield processed and losses from the machine.
		+
		+	{\| class="wikitable" style="text-align: center;
		+	\|style="width: 30%"\| C<sub>pk</sub>
		+	\|style="width: 30%"\| Process Yield
		+	\|-
		+	\|0.5
		+	\|86.8%
		+	\|-
		+	\|0.8
		+	\|98.4%
		+	\|-
		+	\|1.0
		+	\|99.7%
		+	\|-
		+	\|1.2
		+	\|99.97%
		+	\|-
		+	\|1.33
		+	\|99.99%
		+	\|}
		+
		+	C<sub>pk</sub> = or >1.33 indicates that the process is capable and meets specification limits. Any value less than this may mean variation is too wide compared to the specification or the process average is away from the target.

← Older revision		Revision as of 19:20, 11 November 2021
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		+	'''Process Capability(C<sub>p</sub>)''' is a measurable property of a [[Process\|process]] to the specification, expressed as a process capability index (e.g., C<sub>pk</sub> or C<sub>pm</sub>) or as a process performance index (e.g., P<sub>pk</sub> or P<sub>pm</sub>). The output of this measurement is often illustrated by a histogram and calculations that predict how many parts will be produced out of specification (OOS). Two parts of process capability are: 1) measure the variability of the output of a process, and 2) compare that variability with a proposed specification or product tolerance.<ref>Definition - What Does Process Capability Mean? [https://en.wikipedia.org/wiki/Process_capability Wikipedia]</ref>
		+
		+
	'''Process Capability Index (C<sub>pk</sub>)'''<br />		'''Process Capability Index (C<sub>pk</sub>)'''<br />
	Process capability index (C<sub>pk</sub>) is a statistical tool, to measure the ability of a process to produce output within customer’s specification limits. In simple words, it measures producer’s capability to produce a product within customer’s tolerance range. C<sub>pk</sub> is used to estimate how close you are to a given target and how consistent you are to around your average performance. C<sub>pk</sub> gives you the best-case scenario for the existing process. It can also estimate future process performance, assuming performance is consistent over time. C<sub>pk</sub> is a standard index to state the capability of one process, the higher the C<sub>pk</sub> value the better the process is. For instance, Machine 1 has a C<sub>pk</sub> of 1.7 and machine 2 has a C<sub>pk</sub> of 1.1. From the C<sub>pk</sub> value, one can derive that Machine 1 is better than 2. Since C<sub>pk</sub> uses specification limits and parts variation (sigma), we can also arrive at the yield processed and losses from the machine.		Process capability index (C<sub>pk</sub>) is a statistical tool, to measure the ability of a process to produce output within customer’s specification limits. In simple words, it measures producer’s capability to produce a product within customer’s tolerance range. C<sub>pk</sub> is used to estimate how close you are to a given target and how consistent you are to around your average performance. C<sub>pk</sub> gives you the best-case scenario for the existing process. It can also estimate future process performance, assuming performance is consistent over time. C<sub>pk</sub> is a standard index to state the capability of one process, the higher the C<sub>pk</sub> value the better the process is. For instance, Machine 1 has a C<sub>pk</sub> of 1.7 and machine 2 has a C<sub>pk</sub> of 1.1. From the C<sub>pk</sub> value, one can derive that Machine 1 is better than 2. Since C<sub>pk</sub> uses specification limits and parts variation (sigma), we can also arrive at the yield processed and losses from the machine.
		+
		+
		+	'''Measuring Process Capability<ref>How to Measure Process Capability [https://quality-one.com/process-capability/ Quality One]</ref>'''<br />
		+	The capability indices can be calculated manually, although there are several software packages available that can complete the calculations and provide graphical data illustrating process capability. For the example in this section, we will utilize a popular statistical software package. For our example, we will utilize data from randomly collected measurements of a key characteristic of a machined part. To better represent the population values, the sample data must be randomly collected, preferably over time from a large production run. A few things to keep in mind:
		+	*Our data is quantitative and variable
		+	*Our data consists of 100 measurements
		+	*The target dimension is 25.4 mm
		+	*USL (Upper Specification Limit) = 25.527 mm
		+	*LSL (Lower Specification Limit) = 25.273 mm
		+	*Range = 0.254 mm
		+	First, we will examine our data with a simple histogram to determine if it could fit a normal distribution. In addition, we can generate a probability plot evaluating our data’s best fit to a line further indicating we are 95% confident that our data fits a normal distribution.
		+
		+
		+	[[File:Process Capability Example.png\|500px\|Process Capability Example]]<br />
		+	source: Quality One
		+
		+
		+	Now let us examine the Process capability report:
		+	*C<sub>p</sub> (Process Capability) = 1.68
		+	*C<sub>pk</sub> (Process Capability Index) = 1.66
		+	Using the graph, we can further evaluate process capability by comparing the spread or range of the product specifications to the spread of the process data, as measured by Six Sigma (process standard deviation units).
		+
		+	Through examination of the reports, we can determine that our example process is in a state of statistical control. All the data points fall well within the specification limits with a normal distribution. A process where almost all the measurements fall inside the specification limits is deemed a capable process. Process capability studies are valuable tools when used properly. As previously mentioned the information gained is generally used to reduce waste and improve product quality. In addition, by knowing your process capabilities, the design team can work with manufacturing to improve product quality, and processes that are “not in control” may be targeted for improvement. During a typical Kaizen event or other quality improvement initiatives, Process Capability is calculated at the start and end of the study to measure the level of improvement achieved. Accurate knowledge of process capability enables management to make decisions regarding where to apply available resources based on data.

← Older revision		Revision as of 18:57, 11 November 2021
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−	'''Process Capability Index (~~Cpk~~)'''<br />	+	'''Process Capability Index (C<sub>pk</sub>)'''<br />
−	Process capability index (~~Cpk~~) is a statistical tool, to measure the ability of a process to produce output within customer’s specification limits. In simple words, it measures producer’s capability to produce a product within customer’s tolerance range. ~~Cpk~~ is used to estimate how close you are to a given target and how consistent you are to around your average performance. ~~Cpk~~ gives you the best-case scenario for the existing process. It can also estimate future process performance, assuming performance is consistent over time.	+	Process capability index (C<sub>pk</sub>) is a statistical tool, to measure the ability of a process to produce output within customer’s specification limits. In simple words, it measures producer’s capability to produce a product within customer’s tolerance range. C<sub>pk</sub> is used to estimate how close you are to a given target and how consistent you are to around your average performance. C<sub>pk</sub> gives you the best-case scenario for the existing process. It can also estimate future process performance, assuming performance is consistent over time. C<sub>pk</sub> is a standard index to state the capability of one process, the higher the C<sub>pk</sub> value the better the process is. For instance, Machine 1 has a C<sub>pk</sub> of 1.7 and machine 2 has a C<sub>pk</sub> of 1.1. From the C<sub>pk</sub> value, one can derive that Machine 1 is better than 2. Since C<sub>pk</sub> uses specification limits and parts variation (sigma), we can also arrive at the yield processed and losses from the machine.
−	~~Cpk~~ is a standard index to state the capability of one process, the higher the ~~Cpk~~ value the better the process is. For instance, Machine 1 has a ~~Cpk~~ of 1.7 and machine 2 has a ~~Cpk~~ of 1.1. From the ~~Cpk~~ value, one can derive that Machine 1 is better than 2. Since ~~Cpk~~ uses specification limits and parts variation (sigma), we can also arrive at the yield processed and losses from the machine.

@@ Line 1: / Line 1: @@
-<title>Process Capability</title>
+'''Process Capability Index (Cpk)'''<br />
 Process capability index (Cpk) is a statistical tool, to measure the ability of a process to produce output within customer’s specification limits. In simple words, it measures producer’s capability to produce a product within customer’s tolerance range. Cpk is used to estimate how close you are to a given target and how consistent you are to around your average performance. Cpk gives you the best-case scenario for the existing process. It can also estimate future process performance, assuming performance is consistent over time.
 Cpk is a standard index to state the capability of one process, the higher the Cpk value the better the process is. For instance, Machine 1 has a Cpk of 1.7 and machine 2 has a Cpk of 1.1. From the Cpk value, one can derive that Machine 1 is better than 2. Since Cpk uses specification limits and parts variation (sigma), we can also arrive at the yield processed and losses from the machine.