Thin client/server computing and Windows, together, form one of the
lowest total cost of ownership solutions for enterprise users
wanting to utilise email and the Web
A closer look
Thin client/server computing is a server-based approach to
delivering applications to end-users. In this model, IT
organisations deploy, manage and support the company's applications
on a server. This architecture allows robust, secure access to any
application across virtually any network, and allows an
organisation to simplify IT administration and gain tremendous cost
savings in user support and in the deployment and management of
their applications.For decades, mainframe systems delivered
applications to users through "dumb" text terminals. Performance
was adequate for the functions available, security was tight, and
the complexities of managing databases and other IT administrative
tasks were almost invisible to the average user. Despite these
successes, mainframes fell far short in cost-effectiveness and the
ability to display Windows-based applications. These limitations
became more glaring as the pace of business accelerated.
Client/server computing was the answer. It allowed companies to
introduce new and updated functionality and applications quickly,
could distribute more information to individual users, gave users a
graphic interface, and offered cost-effective scalability to keep
up with business growth.In addition, client/server computing
introduced democracy to computing by putting on users' desktops a
complete system that could store applications and megabytes of data
locally. This freed users to do large amounts of local processing,
and knowledge workers enthusiastically tapped the PC's power for
word processing, spreadsheet analyses, design, data analysis, and
much more. Although a solid success, this computing model did
present some issues: companies began to lose control of their data,
many users did not necessarily need the power of the PC and
struggled with its complexity. Software updates and upgrades were
often messy and expensive, and the total-cost-of-ownership was
surprisingly high.In response, companies began to simplify their
server infrastructure by creating a form of centralised
client/server computing that drew their servers into a central
location. This centralisation enabled companies to pull application
and database servers into a more secure, more manageable
environment, but it did nothing to help the end-user nor did it
assure data security or resolve system administration issues.
The
rise of thin client/server computingClearly the next step is to
simplify the model of computing. Thin client/server computing is
the evolutionary model that retains the benefits of client/server
computing, but lowers the cost-of-ownership through simplification
for end-users and IT departments. It helps individuals not
requiring the expandability of PCs, and it helps system
administrators simplify the task of managing the total
environment.Thin client/server computing allows IT departments to
establish direct control over the essential parts of their IT
environment. For example, applications and data are supported and
managed at the server in thin client/server computing. That allows
IT departments to update and upgrade software, perform data
backups, test and deploy applications, and other data centre
activities in an efficient manner uniformly and securely across the
environment, all without disrupting end-users.
Who should use
thin client/server computing?Thin client/server computing is
ideally suited for "task-oriented" end-users. This global term cuts
a cross-section to encompass people in manufacturing, clerical,
customer service, and some data analysis, technical and
professional positions. The common denominator is that
"task-oriented" end-users spend most of their time using a limited
number of applications to perform data entry and lookup. They may
use word processing and similar applications, but they primarily
focus on accessing line-of-business applications. One should not
fall into the trap of assuming this definition only applies to
"simple" applications. In fact, they encompass such complex
environments as Enterprise Resource Planning (ERP) systems and
applications that access numerous databases.A partial list of
"task-oriented" end-users would incorporate such positions as:
reservation clerks for hotels, airlines, car rental firms etchelp
desk operatorsdata entry/data lookup points in hospitals and
nursing homesretail point-of-salemanufacturing shop floor
workersbank tellersstockroom and shipping clerksorder entry
clerksstock-brokersestate agentsinsurance agentsA thin client is a
desktop device that is focussed on delivering the lowest cost, most
secure, and most manageable graphic client solution. Recent years
have seen the emergence of three thin client alternatives: the
NetPC, network computers (NC), and Windows-based terminals. They
differ in the amount of local application processing each support,
the capabilities of the operating systems, and the disk drive
configurations possible. Most importantly, they differ in their
philosophical approach to simplification and cost containment.With
NetPCs, processing occurs on the desktop, not on the server, making
it a PC with centralised management capabilities. NetPCs are sealed
desktop PCs with no user-accessible input/output devices (no floppy
drive and no CD-ROM). Administrative functionality varies, but
usually includes extensive capabilities to monitor and update a
user's software and system configuration. Because NetPCs are
sealed, users cannot introduce viruses, corrupt data or add new
circuit boards by actions at the desktop, so data security is high
and system administration is much easier than with standard PCs.In
concept, Java-based Network Computers (NCs) rely heavily on
downloading small components of the applications upon user demand
for local processing. NCs have many of the virtues of thin
client/server computing: they are simple, low-cost devices, and
they are easy for system administrators to manage from a central
point. However, they depend on a still-developing technology, and
implementing the architecture requires large up-front investments
in designing, testing, and deploying applications as Java-based
components.Windows-based terminals are the "thinnest" of all of the
thin client devices and hence offer the lowest cost and best
manageability of all of the solutions. They rely on a 100 per cent
server-based model of computing, where all application processing
and storage is conducted at the server. Windows-based terminals are
essentially intelligent display devices that present a graphical
user interface (GUI) to the user. They pass all user-keystrokes and
mouse clicks directly to the server for processing. The server,
which runs a separate session for each user, receives and
interprets the keystrokes, then performs all application processing
including retrieving and updating data. The results go back to the
Windows-based terminal for display resulting in an extremely simple
and efficient process.
Thin client/server computing with
Windows-based terminals: the next step forwardWindows-based
terminals are low -cost, graphical desktop devices that can display
applications from a Windows NT server or can access UNIX and legacy
applications through emulation software. They have no local
operating system beyond a small one that is preloaded on internal
firmware. This OS communicates with a server running multi-user
software such as the recently released Windows NT Server, Terminal
Server Edition or Citrix WinFrame (for Windows NT 3.51). They do
not support a hard drive, but will allow users to attach a floppy
drive or a local printer to serial and parallel ports on the
backside. The server (or network of servers and disk arrays) holds
100 per cent of the application software and all data. Software
accessible through Windows-based terminals and the multi-user
server software encompass essentially all Windows-based
applications, including such standard applications as word
processing programs, spreadsheets, email, and Internet/intranet
browsers. The result approaches one of the computing industry's
most important goals: low-cost universal access to applications
located throughout an organisation.
Benefits of Windows-based
terminalsInternational Data Corporation forecasts that
Windows-based terminals will achieve wide-spread acceptance in the
marketplace, growing at a compound annual growth rate of more than
100 per cent per year for 1998 through 2002.Windows-based terminals
are popular through their ability to:Simplify and improve IT
administration through better system-wide controlLower
total-cost-of-ownership per userIncrease data integrity and
securityLengthen desktop longevityCentralise resourcesWe will now
examine these five benefits in greater detail:
Simplifies and
improves IT administrationWindows-based terminals require a
server-centric architecture that centralises resources,
applications and data. This centralisation leads directly to a
wealth of productivity improvements and cost savings. For example,
upgrades and backups are easier and more consistent with IT
practices because IT has direct control for all applications and
data. Company-wide practices for security, virus protection,
disaster recovery and Internet access is all made easier to plan
and implement. Another example is that deployment of Windows-based
terminals is fast and straightforward, especially since most
companies will implement a standardised desktop configuration. This
same uniformity also greatly simplifies help desk support, making
it both more efficient and more effective. Moves/adds/changes are
also easier.The list goes on and on. The key point is that
Windows-based terminals simplify administration and help create a
more controlled environment that supports excellent data integrity,
data sharing, and business continuity.
Lowers the
total-cost-of-ownershipThe Total Cost of Ownership (TCO) for a
networked PC has four components: end-user operations,
administration, technical support and capital. Gartner Group
further divides these four components into asset management, formal
and informal end-user training, security administration, new
software and updates, moves-adds-changes (MAC), help desk,
configuration planning and review and 50 more
subcategories.Projected savings depend on the mix of applications
and other factors, but there is agreement that the largest savings
come from dramatic reductions in end-user operations costs because
Windows-based terminals are so simple to use and are centrally
managed. With Windows-based terminals in place, end-users get the
full benefits of a graphic user interface, but without some of the
complexities normally found in a PC. There is no software to store
or update, no local data to secure, fewer parts to configure and
repair, fewer opportunities to tinker with the device and much less
training to reach and sustain maximum productivity.For
administrators and IT departments, Windows-based terminals allow
easier and more effective user support, simplified configuration
and repair, secure data in a centralised facility, faster and more
uniform software updates, and a way to achieve consistent standards
and policies. Decreasing the number of supported platforms results
in initial purchase and installation cost savings, and in many
cases IT costs are reduced.
Increases data integrity and
securitySystem administrators will tell you that users will do
amazing things with desktops. Unfortunately these things may
include such dubious acts as injecting viruses from floppy disks,
loading multiple versions of a standard company application, or
establishing local data stores that become out-of-date. The
restricted functionality of Windows-based terminals eliminates the
opportunity that can lead to difficulties. Specifically, the
terminals prevent users from storing data locally or from
introducing new data or software except through key strokes within
a standard application. The result ( lower risks and less time
spent undoing problems.
Lengthens desktop
longevityWindows-based terminals offer superior investment
protection from technical obsolescence when compared with PCs,
NetPCs, and NCs. Why? Because there is so little in Windows-based
terminals to upgrade. And when a change does occur, administrators
can make the update at the server and deliver it over the network.
Predictions are that the upgrade cycle is four years or more longer
than any other graphic desktop device available.
Centralises
resourcesThis operates on two levels. The obvious one is
hardware-related: the servers and disk arrays supporting
Windows-based terminals are usually in a centralised location for
ease of administration. This means users can share storage, memory,
and processing power. On a deeper level, the company's data is also
centralised and shared among users, thereby creating an environment
that accelerates business processes and improves information
sharing and co-ordination.
Issues to considerAchieving
optimal benefit from thin client/server computing encompasses
everything from proper sizing of servers and disk storage to
network bandwidth and IT procedures and policies. Developing and
implementing such total solutions are familiar tasks to IT
departments of companies coming from the mainframe and UNIX worlds.
However, companies that approach thin client/server computing from
a PC-oriented perspective may find that they need to incorporate
more robustness and assure more consistency across these
areas.
Server performance plays a crucial roleThe server
delivers applications to end-users in one of two ways: The server
performs application processing and sends the results to the user
The server downloads applications or components to temporary cache
on the thin client device for short-term use by the end userIn
either case, the server repeats this delivery process periodically
as the end-users perform their tasks. If the server is unavailable
or unresponsive, the end user cannot continue the application until
the server becomes available. Clearly, the potential for business
disruption is high if the server does not perform to end-user
requirements.There are many ways to evaluate performance and set
requirements, but two measures stand out: server availability and
response time for end-users. Availability is a measure of per cent
uptime for the system. In thin client/server computing, minimum
availability requirements depend on the criticality and timeliness
of the tasks being done by the company's end-users. Because thin
client/server computing solutions often involve real-time data
entry and data lookup, they generally fall into the category of
business-critical systems. Response time for end-users is the
length of time between sending a request to the server and
receiving the appropriate information at the desktop. An overloaded
server may have excellent availability, yet not meet user
requirements because it supports too many users, runs
compute-intensive applications, or encounters bottlenecks accessing
disk arrays. Further complicating an evaluation is that response
time is not a one-time measurement ( it requires continual
reassessment. For example, a growing business may find its high
performing environment changes into one with poor response time as
the number of users and total demand increase. The best solution is
to select and install scalable servers that provide an easy,
cost-effective path for IT to add more of the overloaded component:
processors, memory, or disk arrays.
AvailabilityWindows-based terminals require an environment
of highly available servers. Providing necessary service levels
requires a comprehensive approach, beginning with the design of the
server infrastructure and of data management strategies. It is
essential that the servers and disk arrays be of the highest
quality. These systems must have a solid track record for
reliability, plus they must contain both redundant and hot
swappable components within the server chassis as further insurance
against server outages. Another key pillar in an availability
strategy is implementing a service and support contract with a
service vendor that is stable, knowledgeable, and able to deliver
active services as well as to provide a guaranteed response time
for repair.
ManageabilityWindows-based terminals' support for
network and system management tools can be one of the biggest
differentiates between thin client offerings. Highly desirable
features in a thin client allow system administrators to:Identify
attached clients and their configurationMonitor status of attached
clientsControl upgrades and changes remotelySend on-screen alerts
and messages to users
End-user performanceStudies show that
end-user performance depends most heavily on sizing the server to
user ratio appropriately and that other factors such as network
bandwidth normally play minor roles. Items to consider when sizing
a server include the number and type of applications being
supported, the number of users and their server-access rates,
expansion plans, and more. From this analysis, one can determine
the most cost-effective number of Intel-compatible processors and
memory to put into the server, while leaving the right amount of
room for growth, either in users or in the number of applications
supported. The application mix in particular is difficult to
assess, but has a direct impact on server duty ratios and tuning
the operating environment parameters. Transaction-oriented
applications, word processors, and email all place significantly
different requirements upon the server. There are no set formulas
to follow, and locating a partner with prior experience can play
big dividends.
ConclusionThin client/server computing is a
server-centric approach to deploying, managing and supporting
applications. The server's reliability, manageability, and
scalability play crucial roles in setting user satisfaction and
establishing a solid return on investment. There are some
infrastructure issues that must be carefully addressed, starting at
design and implementation, but an experienced technology partner
can help companies work through these issues and optimise the
benefits of thin client/server computing. Windows-based terminals
are attracting more and more attention, and fuelling the move to
thin client/server computing. Their appeal is their simplicity and
their suitability for so many situations. As a result,
Windows-based terminals are a powerful tool to achieve solid
reductions in a company's total cost of ownership for desktop
computing without lowering the productivity of
end-users.
Compiled by Mike Burkitt(c) Hewlett-Packard
Corporation 1998