no that is not what I want.
I want to merge iteration results in feature class
I can do this if I know how can I make one tool inside model not run except the last iteration.
so the first merge is to merge the results of an iterator A quick tour of using iterators—Help | ArcGIS for Desktop
and if you have separate processes, you can merge the separate processes... which may have an iterator in them... into a final output.
So you have merging results of branched processes, merging the results of an iterator and merging the results of multple processes. The tools are all outlined in the lines.
I didn't find in that link any topic about merge the results of an iterator A quick tour of using iterators—Help | ArcGIS for Desktop .how can I do that??
then I can't separate my processes ,because it only one processes but every iteration give me other feature,
I use feature selection iteration . so every iteration different result , and I want to add all result in one feature class.
so every iteration produces a new output... correct? If it does, then you can merge those results using the conventional merge tool.
if you want to iterate through featureclasses, or a whole list of things... you use an iterator.
if you want to merge the results of separate or parallel processes, you merge the branches together with the merge branch tool
if your model is getting too complex.. it is time to break up your processes into separate models and leave them separate.
A picture of your model would help.
Perhaps others may have suggestions given none has been of use so far.
I tried to separate my model sub model for iteration and other to put first one and merge tool,
and I use variable substitution for sub model output , and the model run but the result was for last iteration only.