According to Forrester Research CEO George Colony, Apple's best days are behind it - from now on, it will just be downhill. Colony believes Apple, without Steve Jobs, is essentially rudderless, heading towards mediocrity.

In a blog post on April 25, Colony explains his theory using a taxonomy from Max Weber's 1947 book, "The Theory of Social and Economic Organization." The taxonomy says that businesses are either "Legal/Bureaucratic," "Traditional" or "Charismatic."

The Power of Charisma

Apple co-founder and former CEO Steve Jobs was, without a doubt, a very charismatic individual. Jobs was not only a visionary, but he had an amazing ability to lure and lead disciples. He had uncanny instincts regarding product design and usability, and he always seemed to know just what consumers wanted and how to deliver it.

Meanwhile, Apple's new CEO, Tim Cook, falls in the "Legal/Bureaucratic" category, according to Colony. Though a "proven and competent executive," Cook lacks the charisma to lead a unique company such as Apple.

"Apple's momentum will carry it for 24-48 months," Colony wrote in his blog post. "But without the arrival of a new charismatic leader it will move from being a great company to being a good company, with a commensurate step down in revenue growth and product innovation. Like Sony (post Morita), Polaroid (post Land), Apple circa 1985 (post Jobs), and Disney (in the 20 years post Walt Disney), Apple will coast, and then decelerate."

Colony's Suggestions for Apple CEO

Colony did not deny that Cook was a competent executive, but believes that Apple will head downwind with him at the helm. Instead, Colony suggested two other Apple executives who, in his opinion, would be better suited for the job. "Without knowing them personally, I would look to Apple executives Jon Ive or Scott Forstall to be CEO," Colony wrote. "From on far they appear to have some of the charisma and outspoken design sense to legitimately lead the company."

Truth be told, whoever is or becomes Apple's CEO from here on will inevitably be compared to the visionary Steve Jobs, and those are some big shoes to fill. Most likely, any such comparison would turn out unfavorable for any post-Jobs CEO. As Colony sees it, Apple is a "charismatic organization" due to Steve Jobs, and cannot thrive without him for long. Apple's current success is largely due to its popular iPad and iPhone devices, but both product lines will likely go underwater within four to five years, Colony said.

Three Things Jobs Took with Him

"When Steve jobs departed, he took three things with him: 1) singular charismatic leadership that bound the company together and elicited extraordinary performance from its people; 2) the ability to take big risks, and 3) an unparalleled ability to envision and design products," Colony concluded in his blog post. In his opinion, Apple needs an extraordinary CEO to thrive, not just a good one. And Cook is just a "proven and competent executive," but that won't do it for such a unique and visionary company.

Do you agree with Colony's opinion? Leave your comments below.

(reported by Alexandra Burlacu, edited by Surojit Chatterjee)