Simon, Thanks for the response again.
I understand a little better now; however some parts of it still leave me a little stumped. How these physical units would be packaged and moved around. If I have a webapp with JSP, Servlets and the other usual bits and bobs. This would be packaged in it's normal war and deployed to the server (which happens to be OC4J just now). I then want a business layer as a component. If this was being deployed somewhere there would need to be some sort of intelligent process which picks it up and registers it somewhere. I suppose a quartz job or a timertask running checks against the file system could do something to this effect, but it feels I would then be adding extra layers of complexity to my application. The way I feel something like this should work for my purposes is a standalone daemon running which manages services and components etc (I am not completely understanding of the exact difference in definition between components, service and contributions I will be honest). This daemon would be have a store of components which it loads when it runs or they are hot deployed and then any other application or web application through the use of the Tuscany library can then start creating objects which this server will provide. This standalone server may be some other application which could be deployed to the web container/sever instead of a separate running process. If I am way off the mark on the merits of SCA then please let me know, but all I know is I am trying to get a more lightweight version of the old JNDI lookup of beans within my web container. :) Any other ideas or suggestions would be greatly appreciated. Thanks again Chris