What Mike is talking about is that if your client has given you the experimental design (the combinations of attribute levels to show in each task), then there is a way to ask our software to import and use that design.
To do that:
1. On CBC's Design tab (after specifying your attributes and levels) generate an 8-version plan using our software that mimics your client's setup (to create a dummy design that you'll end up replacing with what the client gave you).
2. Export the dummy design using the Export button from the Design tab. This creates a .csv file that you can open with Excel.
3. Open the design file CBC created, and following that same format, overwrite it with the design your client gave you. Save the .csv file.
4. From the Design tab, click the import button and browse to the .csv file (that you modified) and import it.
5. Finally, run Test Design to make sure the design you have imported seems efficient to estimate the effects you are interested in.
Please note that now SSI Web will automatically hand out the design to subsequent respondents (respondent #1 to design #1, respondent #2 to design #2, etc). But, that also means that a respondent who is incomplete will get assigned a version of the plan...the next respondent coming to the survey gets the next version, etc. So, incomplete respondents will create small deficits in the versioning. Usually, those holes tend to balance out, though.
Experimental designs with many versions in CBC can handle quite well what would appear to be quite bad balance in actually completed surveys. This often freaks clients out, because they think they need near-perfect balance to get good results. But, if the versioning plan is initially created well (wherein each version has a balanced presentation of levels and is nearly orthogonal within the version), then even pretty poor balance in handing out the designs causes very little problem for unbiased and precise utility estimation.
I think there are more sophisticated ways to try to use quota control to hand out specific versions...to obtain better balance in the presence of incompletes...but I don't know the details of how to do that. And, it's most likely overkill to do anyway. If you really MUST have near-equal counts on your versions, then you should call our technical support line and see if the wizards there (who know more than I do on these mechanical issues) can help.