Production activities for the iPhone 5S should begin by end of July leading to its rumoured September release date though component issues would likely limit the initial batch of global shipment for the iOS 7-powered device, new reports said.

Assembly of the 2013 iPhone edition will be ramped up by the last week of July, according to reports by AllThingsD, signalling the handset's approaching debut that analysts said will happen in the last month of Q3 2013 or first week of October at the latest.

Apple has actually commenced the iPhone 5S production in June though it was mostly in small batches, MacRumors reported Jefferies analyst Peter Misek as saying.

What will take place over the next two weeks represents the tech giant's major for Q4 2013 - the market entry of the next-generation iPhone, the introduction of the low-cost iPhone Lite and the twin debut of the refreshed iPad 5 and iPad Mini 2.

It appears, however, that Apple will encounter a minor glitch that could shave off the target iPhone 5S out by three million units, DigiTimes said in a new report. This suggests that shipment volume for the handset will not reach the optimal point until the 2013 holiday quarter.

Overall production, the same report said, is hampered by poor production yields of the fingerprint scanner and LCD driver chips that will be used on the upcoming handset.

Apparently, the fingerprint scanner problem is being blamed on Taiwan Semiconductor Manufacturing Company (TSMC), which Apple tapped to mass produce the biometrics technology it obtained from AuthenTec last year.

Despite the production challenges, Apple is upbeat that the iPhone 5S will see the light of the day as scheduled, MacRumors said, pointing to an earlier statement made by Apple chief executive Tim Cook.

Mr Cook has expressed confidence that Apple's production and release targets starting this year through 2014 will take place as scheduled. He pointed to the company's vast supply chain, which should be enough to mitigate negative effects of supply issues and below par performance of certain manufacturing partners.

The Apple CEO hinted too that big surprises from the tech giant will start rolling out by fall of 2013, further giving credence to analysts' forecast that release date for the iPhone 5S is within September, to be followed in quick succession by the iPad 5 and iPad Mini 2 - both physically redesigned for slimmer profiles.