Multiple Dependent State Research Articles

A control chart for an exponential distribution using multiple dependent state sampling

In this paper, we will present a control chart for exponentially distributed quality characteristics using multiple dependent state sampling. The proposed control chart has double control limits with two control coefficients, which is based on a normal approximation through transformation. The control coefficients are determined by considering the average run length (ARL) when the process is in control. The ARL for the shifted process is reported according to various shift ratios. The efficiency of the proposed control chart over the existing t-chart is compared in terms of the ARL.

Multiple dependent state variable sampling plans with process loss consideration

In the literature, multiple dependent state variable sampling plans are available that does not constitute the process loss and hence are unable to distinguish among the product that falls within or outside specification limits. In this manuscript, the multiple dependent state variable sampling plans with process loss consideration are proposed. The designed parameters of the proposed plan are found by satisfying the vendor and buyer risks at various acceptable quality level and limiting quality level. The advantages of the proposed plan are discussed compared with the existing plans using the process loss function (Yen and Chang Commun Stat: Simul Comput 38:1579–1591, 2009) and Aslam et al. (Commun Stat-Theor Method 41:3633–3647, 2012). A real industrial example is included to illustrate the proposed plan.

Multiple Dependent State Sampling Plan Based on Process Capability Index

Abstract This paper extends the idea of multiple dependent state sampling plans to the case of using process capability index when the quality characteristic of the product follows the normal distribution. The plan parameters are determined using the optimization process with minimum values of sample size so that the specified producer’s risk and consumer’s risk should be satisfied simultaneously for given values of acceptable quality level and limiting quality level in terms of fraction defective beyond two specification limits. The plan parameters are determined under symmetric and asymmetric cases of fraction defective. The advantage of the proposed plan is discussed over the single variable sampling plan. A real example is presented to illustrate the proposed plan in practice.

Multiple dependent state sampling plans for lot acceptance based on measurement data

This paper proposes a multiple dependent (or deferred) state sampling plan by variables for the inspection of normally distributed quality characteristics. The decision upon the acceptance of the lot is based on the states of the preceding lots (dependent state plan) or on the states of the forthcoming lots (deferred state plan). The lot acceptance probability is derived and the two-point approach to determining the plan parameters is described. The advantages of this new variables plan over conventional sampling plans are discussed. Tables are constructed for the selection of parameters of this plan under the specific values of the producer’s and consumer’s risks, indexed by acceptable quality level and limiting quality level, when the standard deviation is known or unknown.

Construction and selection of multiple dependent (deferred) state sampling plan

Tables have been prepared for the construction and selection of multiple dependent (deferred) state (MDS) sampling plans of type MDS-(c1,c2). These plans are compared with conventional sampling plans (such as single and double sampling) and it is shown that MDS-type plans require a smaller sample size. A special feature of the MDS-(0,1) plan is highlighted and its design procedure is indicated.