Experienced CIOs have learned the hard way that achieving tangible benefits early in the technology lifecycle is no easy \n\nmatter\u2014whether its OO, CMMI, ITIL or SOA. Cloud computing shows promise and demands attention, but the related hoopla needs to \n\nbe tempered with a good dose of business sense. The cloud, regardless of its variety, should never be considered an all-or-nothing proposition. \n\nRather, it's a melting pot in which the mixture's properties will gradually change over the coming years.[For timely cloud computing news and expert analysis, see CIO.com's Cloud Computing Drilldown section. ]The cloud trend should continue to gain traction as both technology and business leaders embrace some of the practical realities involved in \n\nintroducing not just a new set of technologies, but accompanying processes and financial models. At the same time, though, CIOs will face a \n\nsignificant hurdle in convincing business partners that there's more than meets the eye in terms of cost and effort. Remember a few years ago when \n\npeople were asking, "Why aren't we using an ERP system?" Yogi Berra might say it's deja vu all over again.Moving from a traditional hosting model to full-scale cloud computing model in one step is neither realistic nor prudent. So for the next several \n\nyears, most enterprises will operate variations of a hybrid cloud model, one in which public and private infrastructure clouds and traditional \n\ndata-center hosting coexist as part of the enterprise infrastructure ecosystem. This mixed environment will give CIOs a lot of room to experiment \n\nwith low-risk public cloud applications before seriously exploring vendor solutions.The "Purpose-Built" Cloud\nExperimentation will be a vital phase in determining the right hybrid cloud path for each organization. \n\nPublic clouds, owned and operated by third parties, offer greater scale and, as a result, greater cost savings. But they are immature, providing \n\nfar less control over SLAs, increased security and compliance concerns, and complex back-end integration. Private clouds are attractive because \n\nthey offer similar benefits to those of a public cloud, but add increased control and advanced customization. With many pros and cons to consider, \n\nthe three operating models\u2014traditional hosting, public clouds, and private clouds\u2014will likely coexist for at least the next three to five \n\nyears, especially for large and mature enterprises. In addition, each model will contribute infrastructure, middleware, and business applications to \n\nthe enterprise technology portfolio.I expect we will see companies travel in two directions. High-volume, high-performance firms that also must meet robust regulatory and \n\nsecurity mandates (e.g., Wall Street firms and other large highly-regulated enterprises) are likely to shift from the current hosting model to a hybrid \n\ncloud model that combines hosting with elements of a private cloud. These companies may selectively adopt public cloud services from vendors \n\nsuch as Salesforce.com, but for the most part, public clouds will not be able to meet their needs for performance, security, and compliance. On the \n\nother hand, small to mid-size companies in less regulated industries, such as retail, may choose to augment their current hosting model with the \n\npublic cloud\u2014able to extract its benefits without the need to meet more stringent requirements.Firms of all shapes and sizes are at least exploring the idea of sending infrastructure, applications, and information to the cloudand they \n\nwould be taking a big risk if they weren't doing their due diligence. As I recently wrote with two of my colleagues, our clients fall into one of six increasingly complex categories in their cloud exploration and adoption. At one end, clients are \n\nsurveying the market or might be using an off-the-shelf cloud application or service (the stock Salesforce.com or Google's Docs and Mail services \n\ncome to mind). Clients at the other end of the spectrum are already using multiple cloud applications that are neatly integrated with corresponding \n\nin-house applications.As a first step in sorting through the hype, an organization must gain a clear view of its systems portfolio in the context of business needs and \n\npain points. Without it, a company will feel the weight of mismatched cloud services and applications\u2014in terms of both cost and flexibility. \n\nThe results of a six-step readiness assessment will guide a company as it engages a few targeted cloud providers to discuss high-priority candidate \n\nsystems for the cloud. In order to "clear the lens," an organization must:\nUnderstand the business demands for new functionality.\nEvaluate the current application and architecture portfolio, in terms of business gaps and technology health.\nDetermine candidate applications by understanding relevant cloud offerings.\nEvaluate opportunities for infrastructure-only cloud services.\nAssess management and operations readiness.\nIdentify early cloud adopters.The pace and direction of each organization's cloud computing migration strategy will differ. But the need for an organization to understand its \n\nreadiness for a new approach to delivering applications is a common thread. With a comprehensive assessment in hand, a CIO can begin \n\nevaluating the company's systems architecture in earnest, and building a roadmap that demonstrates the business value in shifting pieces to the \n\ncloud, the company's readiness, and potential vendor fit.In other words, you'll want to know the probable outcome before dropping elements into the melting pot.Chris Curran is Diamond Management & Technology Consultants' chief technology officer and managing partner of the firm's technology \n\npractice. He writes the CIO Dashboard blog, and can be reached at Chris.Curran@diamondconsultants.com or @cbcurran on Twitter. Diamond's "Seeing \n\nThrough the Clouds" seminar is Nov. 5, seethis for more \n\ninformation. Follow everything from CIO.com on Twitter @CIOonline.