Initially, Böhme planned to cross river Drina with 342nd division and to destroy rebels in the Mačva region attacking them from south toward north. He changed his mind because he was concerned that this tactic would expose flanks of the 342nd division to attacks of rebel forces from mountain Cer-Iverak. Based also on the proposal of Kvaternik, who pointed to the experience from the 1914 Battle of Cer when the majority of Austro-Hungarian troops attacked Serbia crossing the Drina only to be defeated by the Serbian army, Böhme adopted the plan to attack rebels with troops crossing river Sava. The final plan for the cleansing operation was simple: to preserve an element of surprise, the 342nd division would be unloaded in the NDH, cross Sava river, clean region of Mačva and then to advance into the rebel-controlled territory in direction North-South. The 342nd Infantry Division arrived to Srem in period between 19 and 21 September. The rebel Attack on Šabac that began on 21 September 1941 has hastened the military engagement of the 342nd Infantry Division.