Is Package.writeExternal(ObjectOutput) the best way to create a binary file of your package that can be read by BinaryRuleBaseLoader.addPackage(InputStream) ? Having generated a package using standard code, I've tried to create a binary file of the package for deployment as below. But when BinaryRuleBaseLoader reads the binary file it raises : Can only add instances of org.drools.rule.Package to a rulebase instance. Looking inside the binary file I can see it doesn't have the first line : ’__sr__org.drools.rule.Package_______@ which is found in packages downloaded from JBRMS. So this code isn't quite working. Please can you help. builder.addPackageFromDrl(source); Package pkg = builder.getPackage(); try{ FileOutputStream tempFile = new FileOutputStream("my.pkg"); ObjectOutput oos = new ObjectOutputStream(tempFile); pkg.writeExternal(oos); oos.flush(); oos.close(); tempFile.flush(); tempFile.close(); } catch(Exception e){ System.out.println(e.toString()); } Regards, Steve Barfield, Developer Application Services FUJITSU SERVICES Cavendish Road, Stevenage, Herts, SG1 2DY * +44 (0) 870 234 8197 (Int: 7444 8197) * +44 (0) 7867 828474 * <mailto:steve.barfield@uk.fujitsu.com <mailto:steve.barfield@uk.fujitsu.com> > Web: http://uk.fujitsu.com <http://uk.fujitsu.com/> Fujitsu Services Limited, Registered in England no 96056, Registered Office 22 Baker Street, London, W1U 3BW This e-mail is only for the use of its intended recipient. Its contents are subject to a duty of confidence and may be privileged. Fujitsu Services does not guarantee that this e-mail has not been intercepted and amended or that it is virus-free.