0To schedule the batch class in minutes/hours, in the finish method we should use System.schedule method which will take 3 parameters Job Name, Chrone Expression and schedulable class instance name respectively.
/*** Scheduling in minutes or hours ***/
//Create object for schedulable class
SchedulableUsage su = new SchedulableUsage();
//Preparing chron_exp
Datetime sysTime = System.now();
sysTime = sysTime.addminutes(6);
String chron_exp = '' + sysTime.second() + ' ' + sysTime.minute() + ' ' +
sysTime.hour() + ' ' + sysTime.day() + ' ' + sysTime.month() + ' ? ' + sysTime.year();
System.schedule('Dep Update'+sysTime.getTime(),chron_exp, su);
