Regarding Half a dozen Sigma quality methodology, process performance are said towards providers while the a sigma level. The better the newest sigma height, the better the process is performing.

Another way to report process capability and process performance is through the statistical measurements of C_p, C_pk, P_p, and P_pk. This article will present definitions, interpretations and calculations for C_pk and P_pk though the use of forum quotations. Thanks to everyone below that helped contributed to this excellent reference.

Definitions C_p= Process Capability. A simple and straightforward indicator of process capability. C_pk= Process Capability Index. Adjustment of C_p for the effect of non-centered distribution. P_p= Process Performance. A simple and straightforward indicator of process performance. P_pk= Process Performance Index. Adjustment of P_p for the effect of non-centered distribution.

Interpreting C_p, C_pk “C_pk is an index (a simple number) which measures how close a process is running to its specification limits, relative to the natural variability of the process. The larger the index, the less likely it is that any item will be outside the specs.” Neil Polhemus

“If you hunt our shoot targets with bow, darts, or gun try this analogy. If your shots are falling in the same spot forming a good group this is a high C_p, and when the sighting is adjusted so this tight group of shots is landing on the bullseye, you now have a high C_pk.” Tommy

In case the vehicle is significantly smaller than the latest driveway (Six Sigma techniques), they does not matter for many who park it precisely in-between; it can match and you have plenty of room towards the sometimes front

“C_pk measures how close you are to your target and how consistent you are to around your average performance. A person may be performing with minimum variation, but he can be away from his target towards one of the specification limit, which indicates lower C_pk, whereas C_p will be high. On the other hand, a person may be on average exactly at the target, but the variation in performance is high (but still lower than the tolerance band (i.e., specification interval). _pk will be lower, but C_p will be high. C_pk will be higher only when you r meeting the target consistently with minimum variation.” Ajit

Such situation including C

“Consider a car and a garage. The garage defines the specification limits; the 321chat türkiye car defines the output of the process. If the car is only a little bit smaller than the garage, you had better park it right in the middle of the garage (center of the specification) if you want to get all of the car in the garage. If the car is wider than the garage, it does not matter if you have it centered; it will not fit. If you have a process that is in control and with little variation, you should be able to park the car easily within the garage and thus meet customer requirements. C_pk tells you the relationship between the size of the car, the size of the garage and how far away from the middle of the garage you parked the car.” Ben

“The value itself can be thought of as the amount the process (car) can widen before hitting the nearest spec limit (garage door edge).C_pk =1/2 means youve crunched nearest the door edge (ouch!)C_pk =1 means youre just touching the nearest edgeC_pk =2 means your width can grow 2 times before touchingC_pk =3 means your width can grow 3 times before touching” Larry Seibel

Interpreting Pp, Ppk “Processes Performance List essentially tries to be certain that when your shot one you may have generated in the techniques are competent to satisfy Customers CTQs (requirements). It differs from Procedure Capabilities in that Procedure Performance merely can be applied in order to a certain batch out of issue. Examples from the group may prefer to become a bit higher in order to feel member of the type on the batch. Techniques Results is made use of whenever process-control can not be evaluated. A good example of this is certainly having a short pre-production work at. Procedure Show fundamentally spends shot sigma in its computation; Processes possibilities spends the process sigma value determined off often the newest Moving Diversity, Variety otherwise Sigma handle charts.” Praneet