I'm afraid I'm not entirely sure what you're trying to achieve.
However if you mean how to plot data such as time to build an app (Design = 10 hours, Development = 90 hours)
SChartRadialDataPoint *designDataPoint = [[SChartRadialDataPoint alloc] init];
designDataPoint.name = @"Design";
designDataPoint.value = @10;
SChartRadialDataPoint *developmentDataPoint = [[SChartRadialDataPoint alloc] init];
designDataPoint.name = @"Development";
designDataPoint.value = @100;
You would then return these data point values from the chart datasource method sChart:dataPointAtIndex:forSeriesAtIndex: (the chart will determine the segment proportions automatically).
I'd recommend taking a look at our 'PieChart' sample project included with your download of shinobicharts. Note that SChartPieSeries is a subclass of SChartDonutSeries and can be used almost interchangably.
I hope that's of some help.