Dear Yateen
I assume that erection commissioning and installation services are being received by you with respect to machines installed in your factory or factory premises and such machines are used in manufacturing of excisable goods. as per the definition of input services, service used by manufacturer whether directly or indirectly, in or in relation to manufacturing of final products shall be treated as input service. further further inclusion part of the definition of input services clearly stated that services used in relation to modersination of factory will also qualify as input services. being so, even if the machine installed or erected or commissioner by using erection commissioning and installation services are not actually used in manufacturing of excisable goods, even though such erection commissioning and installation services would qualify as input services.
You are eligible to take the credit of service tax paid on erection commissioning and installation services.