# Design specifications are within nominal value or

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design specifications are within nominal value, or target, and tolerance given an allowance above or below a nominal value (Krajewski et al., 2019, p. 117). The original Wild Dog Coffee Company location produced a 50 beverage iteration chart with times of completion. Using the process capability index and ratio, a determination of defective outputs relative to the upper and lower specifications can be evaluated quantitatively to determine of a process is capable (Krajewski et al., 2019, p. 117).
PROCESS IMPROVEMENT PLAN: WILD DOG COFFEE COMPANY 7 1.5 1.6 1.7 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3 3.1 3.2 3.3 3.4 3.5 More 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 Histogram Minutes to Complete Beverage Number of Iteratons at each Time The process capability index measures how well the process is centered and if variability is acceptable (Krajewski et al., 2019, p. 117). This process is concerned with how well the process distribution is centered relative to specifications and checks to see if the process average is at least three standard deviations from the upper and lower specifications (Krajewski et al., 2019, p. 117). The process capability index is expressed as: C pk and the formula for calculation is: C pk =Minimum of ´ x Lower Specification 3 σ , Upper Specification −´ x 3 σ ¿ The process capability ratio is the tolerance width divided by six standard deviations (Krajewski et al., 2019, p. 118). The process capability ration is used in conjunction with the process capability index and if a process is capable, it will have a process distribution whose extreme values fall within the upper and lower specifications and be plus or minus three standard deviations (Krajewski et al., 2019, p. 118).The process capability ratio is expressed as: C p , and the formula for calculation is: C p = Upper Specification Lower Specification 6 σ A process capability ratio is only calculated if the process capability index are unacceptable (Krajewski et al., 2019, p. 118). If the ratio is acceptable, the focus should be on centering the process; if the process is not acceptable, the focus needs to be on reducing variability in the process until it passes the test (Krajewski et al., 2019, p. 118). Process Capability Results C pk = 0.52 C p = 0.53
PROCESS IMPROVEMENT PLAN: WILD DOG COFFEE COMPANY 8 The capability index and capability ratio are useful in the valuation of current processes and the determination if processes are meeting acceptable standards of performance. Centered The Wild Dog Coffee Company’s current espresso production process is not centered and gaining insight into the current performance metrics can help determine what processes should be monitored and tracked to facilitate improvement. 3-Sigma Performance The process capability must be compared to a critical value to judge whether a process is capable (Krajewski et al., 2019, p. 117). A company striving to achieve three-sigma performance will use the critical value for the ratio of 1.0 and processes producing services or products with less than three-sigma performance will have values less than 1.0 (Krajewski et al., 2019, p. 117).