One of the biggest benefits of the cloud, ‘Dynamic Scaling,' goes hand-in-hand with multi tenancy. If your application has a fixed group of users, you can easily predict the server load and still handle it with a typical data center. However, a large number of users, basically multi tenants, makes the cloud platform most efficient in terms of usability of the application and ‘Do More With Less Resources.'

Some of the other characteristics of a typical multi-tenant application, benefited by Cloud are:

• Large global population working across time zones
• Quite possible that at any time 100% usage is not possible, but rather 70-80%
• Application serves a global common process for most, but yet is customizable for local needs

Multi Tenancy & Large Enterprises:
Many IT groups within the large enterprise including CXOs view multi-tenant applications as the one that hosts a disparate group of individuals or organizations. The main reason being the most successful cloud applications that come to mind are:

• Salesforce.com: a SaaS-based CRM application for various businesses using common framework and multi tenancy model
• Microsoft Dynamics CRM Online offering
• Multi-Tenancy IaaS/PaaS offerings from Amazon or IBM or Microsoft Azure

So the common misconception is that multi tenancy is all about resources shared by more than one organization. This leads to many discussions on Multi Tenancy Cloud, cut short by the stakeholders with the statement that ‘We Don't Need Multi Tenancy'.

However, through careful analysis of how the enterprise applications have been built and managed, we find that the multi tenancy is very much a feature of large enterprises, and utilizing a Private or Public cloud model with a multi-tenant attribute for their existing applications will definitely provide value for large enterprises.

Various Forms of Multi Tenancy in Large Enterprises
Acquisitions & Mergers: In today's economy, mergers are not something controlled by IT systems but rather inevitable. Invariably during mergers, industry analysts have advocated the following with respect to the common IT systems between the two merging entities.

• Absorption: Selection of one of the existing system landscape
• Best Of Breed: Using selective systems from each entity which are considered to be best
• Co-Existence: Retention of applications from both entities
• Green Field: Develop completely new systems common to both entities.

Again each of these approaches has their own advantages and disadvantages. However, the underlying fact is that mergers make an enterprise automatically MultiTenanct and hence the benefits of the Cloud can automatically be realized if the applications are transformed to take the advantages of multi tenancy.

Globalization & Emerging Markets: Most successful global organizations today started initially as a local organization specific to a particular region. But the growing speed of markets will automatically force the large enterprises toward emerging markets.

This means the IT systems that cater to a local region need to take care of global or multiple regions. The concepts like Localization and Internationalization are built in part of many frameworks such as .NET or Java EE, but they are meant to solve the language barriers, cultural issues and other user interface-specific characteristics.

The biggest challenge is more with the business processes, which will continue to be unique for each region due to the country-specific tax laws or statutory needs and any specific logistic issues in the respective regions.

This automatically makes a regional application into a multi-tenant application when it is expanded to a global user base, because invariably the application needs to behave differently for different regions, making it more like a classic multi-tenancy model.

Multi-Vendor Collaboration: In most ERP systems for enterprises, more options are built so that multiple vendors collaborate and provide their specific details for the overall supply chain process. One such example is the ability of the vendors to log on to supply chain systems and print their purchase orders and make changes to delivery schedules.

For example, Microsoft Dynamics ERP Systems provide a lot of ability to connect with suppliers and customers. The following are some of the features of Microsoft Dynamics ERP Systems:

• Make business information and processes available to suppliers so they can update inventory and shipping information; review orders, invoices, and sales projections; and easily share large files while reducing email exchanges.
• Simplify communication with partners in different time zones and geographic regions by communicating through a business portal on your extranet.

Summary
Some of the above points makes it clear that Multi Tenancy indeed forms a part of the applications of large enterprises and multi tenancy is already in use in large enterprises, so migrating them to private clouds with appropriate dynamic scaling factors will definitely help enterprises reduce capital and operational expenditures.