There has been a lot of concern lately that iPhone 5 demand has slowed, based on rumours that suggest Apple has cut back on orders from its suppliers who make the iPhone 5. However, an ex CEO of Apple recently suggested that Apple is moving to a six month product cycle, and an Apple analyst has suggested that the reason for Apple's slow down on iPhone 5 production is because the iPhone 6 of iPhose 5S will soon be launching.

As we reported last week, former Apple CEO John Sculley told CNBC: "I think they're going through a very significant change now in terms of product cycles. Traditionally Apple introduces products once a year; now it's really introducing products twice a year."

Sculley continued: "The complexity of that from a supply chain is immense, and Apple seems to be doing it well. So, I think that people are underestimating just how well Apple is run, and just how successful the company can be when it gets to that twice-a-year product introduction cycle."

Sculley's theory suggests that Apple is managing production of the iPhone 5 much better than people realize, and could indicate that the company has plans afoot for a new iPhone 5S or iPhone 6 at some point in the new year and therefore doesn't need to build as many iPhone 5 models.

Apple analyst Horace Dediu of Asymco suggests that Sculley might be on the money with his observation. He writes: "Sculley’s comments prompted me to weigh the possible evidence that this [Apple moving to a semi-annual cycle] is happening".

Dediu notes the following indications that Apple is moving to an update cycle of more than once a year.

1) All Apple's major products were updated this autumn. A move that Dediu describes as "unprecedented".

2) The iPhone has already launched in "nearly the entire distribution list". He suggests: "It indicates no channel fill will be happening past Q1".

3) Apple's once-yearly update cycle leads the company with "an inability to meet demand for half the year and a sales lull for the other half. Clearly this is suboptimal," writes Dediu.

4) Dediu notes: "Production for Apple has tended to be 'bursty' with breakneck round-the-clock crush followed by periods of idle time and re-tooling. This is not only inefficient but it also creates strain and stress and lowers morale."

5) He notes a recent bursts in CapEx and suggests it "may have to do with tooling-up Samsung’s replacements," or "it may also imply a move to a more rapid product cycle."

6) And then there are the rumours that the iPhone 5S is already in pre-production.

Dediu notes that these are all "circumstantial pieces of evidence" but he suggests that they "corroborate Sculley’s claim of a six month product cycle."

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