Dear Bhimappa
Both KP06 and KP26 are planning Tcodes and are used to plan your cost centres for various activities.
In KP06 you plan the cost to be incurred at the Cost center. For example You may plan Wages, Power,Maintenance cost elements to your production cost center for a particular period say one month or one year.
In KP26 you plan activities to be performed at the cost center. Like in above example you can plan 2000 Hrs of labor and 1000 KW of power and 100 Hrs of maintenance.
Based on above planning you calculate planned activity prices (KSPI) which are used further to calculate standard cost of materials and for other purposes also.
Regards
Rajneesh Saxena