Planned Activity Rate not maintained

Dear Guru`s,

Today I experienced very unusual scenario.....

While executing month end process I found that Planned Activity rates are not maintained.... Yes Planned activity rates are not maintained and all process has been done till costing closing....What I mean to say that Std. Price for material has been released and Production confirmation both Planned and Actual has been done but the User forgot to execute Kp26 step....

My question is this what will be the consequences if Planned rates are nit maintained and if I proceed with my costing closing....????

Can it be rectified on this stage????

Regards

Nitisha