Signed sequential rank Shiryaev–Roberts schemes

We develop Shiryaev–Roberts schemes based on signed sequential ranks to detect a persistent change in location of continuous symmetric distribution with known median. The in-control properties these are distribution-free, hence they do not require parametric specification an underlying density function or the existence any moments. Tables control limits provided. out-of-control average run length gauged via theory-based calculations and Monte Carlo simulation. Comparisons made two existing distribution-free schemes. conclude that newly proposed scheme has much recommend its use practice. Implementation methodology is illustrated application data set from industrial environment.