The Desktop Transformation Assessment (DTA) forms an integral part of the overall Desktop Transformation Model (DTM) by providing clear guidance on how to turn “Wow” into “How”.  During this series of blog posts, I’m discussing the seven key phases that make up the DTA:

  1. Define Business priorities
  2. Application Assessment
  3. User Segmentation
  4. Capabilities Assessment
  5. High-Level Design
  6. Desktop Transformation Roadmap
  7. High-Level project plan

Now that the business priorities have been established, the application assessment completed and the user segmentation finalized, it’s time to begin the capabilities assessment – the last step prior to the High-Level Design.  In this phase of the DTA, the current state of the environment will be evaluated so that the starting point for the High-Level Design can be established.  You’ll also want to assess any planned projects and initiatives so that they can be factored in to the High-Level Design.  And of course, you need to capture and prioritize any potential risks that could affect the success of the desktop transformation.

The capabilities assessment evaluates the existing infrastructure by examining the readiness of the following ten key areas – each of which will form part of the foundation that supports the proposed virtual desktop solution:

  1. Users and Applications.Establish the pain points experienced by the user community by distributing a questionnaire to a representative sub-section of users.  The characteristics of the user estate need to be established so that that the High-Level Design can be scaled appropriately.  Therefore it’s necessary to capture the following metrics:
    1. Total number of users (available from the user segmentation phase)
    2. Number of third-party users
    3. Number of concurrent internal users
    4. Number of concurrent remote users

    In addition, identify the application delivery mechanism(s) currently in use and establish whether the applications have already been packaged.

  2. Client Devices and Mobility Requirements. The High-Level Design will need to consider the client devices in use so that an appropriate FlexCast model and HDX technology can be selected.  There are a number of different vendors offering desktop inventory software, some of which were discussed during my blog on the application assessment phase of the DTA.  The current strategy for supporting mobile workers should also be evaluated.  This is also a good time to check that the current laptops are listed on the XenClient Hardware Compatibility List (HCL).
  3. Desktop Installation and Characteristics. Identify whether the existing desktop installation process will be suitable for a virtual desktop solution. Ensure that the build process is documented, repeatable and requires any updates to be fully tested.  In addition, establish which applications are included within the base image.
  4. Desktop Access. Evaluate how the user community currently gains access to their desktops and applications both internally and externally.  Determine whether the existing access infrastructure can be leveraged within the High-Level Design including the VPN solution, load balancers, Web Interface Servers, Merchandizing Server, Two-Factor Authentication, etc.  If multiple active/active data centers are in use, how are the external users routed to the most appropriate data center – Global Server Load Balancing?
  5. Virtualization and Storage. Perform a thorough review of the virtualization and storage solutions currently in use.  Establish their resilience, scalability, performance and redundancy so that the most appropriate solution can be selected for the High-Level Design.
  6. Windows Server and Active Directory. The Active Directory environment should be reviewed to determine whether the OU structure, group policies, user profiles, logon scripts and delegated rights are ready to support desktop virtualization.  Review the build process for Windows Servers to determine the different configurations available, for example operating system version, system architecture, processor/memory specification, disk space, etc.
  7. Network Architecture. So that the High-Level Design can determine if there’s sufficient network capacity, map the location of the users against the existing network topology.  Review existing monitoring solutions for periods of latency, lost packets and insufficient bandwidth.  Check that there are a sufficient number of IP addresses available to support the proposed virtual desktop solution. Also, examine the topology for single points of failure and potential bottlenecks as well as determining whether Quality of Service (QoS) and network optimization devices are available.
  8. Citrix XenApp. If Citrix XenApp is already in use, evaluate this environment, including the License Server, and determine whether it can be leveraged in the High-Level Design to support hosted shared desktops, VM Hosted Apps and application streaming – as appropriate.
  9. Risk Tolerance Planning. It’s important to check that the supporting infrastructure offers a similar level of redundancy to the the virtual desktop solution. Also, verify that the business has a suitable disaster recovery plan in place and that is has been adequately tested.
  10. Training and Certifications. Desktop transformation projects should involve training for both support staff and end users.  During the capabilities assessment, capture the current certification level of the support staff as well as their experience across the environment including Citrix, Microsoft, Storage, Networking, Virtualization, etc.

The findings from the capabilities assessment should be documented so that everybody is aware of the current capabilities and the key risks that have been identified.  And now that the capabilities assessment is completed you’re over halfway done the DTA. Check back soon for details on the next step in the DTA – High-Level Design.

Andy Baker – Architect
Worldwide Consulting
Desktop & Apps Team
Virtual Desktop Handbook
Project Accelerator