Hello experts,
I've tried to use HarveyBallMicroChart, I think it's designed to show little pie chart, and it's make sense that there're several pieces of pie in the chart.
But it seems it can only show one piece in the pie chart, like this:

even I've add the second piece:

Here is the source code:
JS Bin - Collaborative JavaScript Debugging
Demo Source Code:
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta http-equiv='Content-Type' content='text/html;charset=UTF-8'/>
<script src='https://sapui5.hana.ondemand.com/resources/sap-ui-core.js'
id="sap-ui-bootstrap"
data-sap-ui-libs="sap.ui.commons,sap.suite.ui.commons,sap.viz"
data-sap-ui-theme="sap_bluecrystal">
</script>
<script>
var complateChart = new sap.suite.ui.commons.HarveyBallMicroChart({
size:"M",
total:500,
totalScale:"Min",
showTotal:true,
showFractions:true,
items:[
new sap.suite.ui.commons.HarveyBallMicroChartItem({fraction:100, color:"Good", fractionScale:"Min" }),
new sap.suite.ui.commons.HarveyBallMicroChartItem({fraction:20, color:"Error", fractionScale:"Min" })
]
});
complateChart.placeAt("content");
</script>
</head>
<body class="sapUiBody" role="application">
<div id="content"></div>
</body>
</html>