Start a service in a separate process android

Check out the process attribute for service in AndroidManifest.xml. You need to change your android:process value to start with a :.

http://developer.android.com/guide/topics/manifest/service-element.html

The relevant section:

If the name assigned to this attribute begins with a colon (':'), a new process, private to the application, is created when it's needed and the service runs in that process. If the process name begins with a lowercase character, the service will run in a global process of that name, provided that it has permission to do so. This allows components in different applications to share a process, reducing resource usage.

The other answer provided doesn't really answer the question of how to start a service in a separate process.

Defining a Process of a Service

The android:process field defines the name of the process where the service is to run. Normally, all components of an application run in the default process created for the application. However, a component can override the default with its own process attribute, allowing you to spread your application across multiple processes.

If the name assigned to this attribute begins with a colon (':'), the service will run in its own separate process.

<service
  android:name="com.example.appName"
  android:process=":externalProcess" />

If the process name begins with a lowercase character, the service will run in a global process of that name, provided that it has permission to do so. This allows components in different applications to share a process, reducing resource usage.

Running on a separate process will not solve your problem. I had the same issue and this is a normal behavior of Android. When you start a Service (not a Foreground Service), even if it is in a separate process, the OS can kill it any time. In your case, if you close the Activity(s)/kill the Application, the OS will normally close the service even if they are in separate processes. You have two options:

1- Start your service as a Foreground Service. In this case the Service will not be closed due to almost any condition. Be aware that the foreground service is designed for specific applications and you will have a sticky notification in the notification center and status bar.

2- Make your service as a Start service (not an IntentService). Then on the onStartCommand of service, return START_STICKY. This will tell the OS, if for any reason you need to close the Service run it again when you have enough resources. In your case, when the user closes the Activity/kill the Application the Service process will be killed anyway, however it will normally reopen.