I am looking into control charts to monitor time between events for rare events. A quick literature review revealed that the following four methods are worth investigating:
Cumulative Count of Conforming (CCC) chart; Cumulative Quantity Control (CQC) chart; the exponential CUSUM and exponential EWMA chart.

I am slightly confused by the terminology and wonder whether exponential EWMA is just a "normal" exponentially weighted moving average? I suspect it isn't but I cannot find literature that explains the difference between the two approaches...if anyone does, I'd be more than happy to look at it.

It also seems that I will not be able to implement the approaches listed above in the R package qcc I have been using so far for simpler spc charts. Does anyone have experience with other R packages which might?