The following assumes your OHS is hosted in MS Windows. An equivalent bash shell script may be easily created to do the same in Linux/Exalytics. The below assumes you have already executed the OHS storeUserConfig process previously documented on this blog.
REM This script sets up our environment variables.
sc start "Oracle Weblogic ohs NodeManager (F_Oracle_Middleware_ohs_wlserver)"
start "StartOHS" /wait /i cmd /c %EPM_INSTANCE_HOME%\httpConfig\ohs\bin\startComponent.cmd ohs_component
Change the "F" in red above to be your EPM system's drive letter. The variable EPM_INSTANCE_HOME is the path to the instance, such as F:\Oracle\Middleware\user_projects\epmsystem1 and I define it in my custom ScriptEnv.bat.