Figure 4
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Web-based LIMS built on Microsoft's .NET framework typically transmit data between the .NET framework and traditional client/server
architectures to offer a web-based application. In such systems, the thick-client is somewhat hidden because it runs in a
browser. However, there is more running on the client than just the browser. A .NET application that runs on the .NET framework
installed on the end-user client is required to render the browser pages from the thick-client server. In essence, the browser
is not showing HTML, but instead, is showing a thick-client-server-like application. In addition, these applications also
rely on the local client for computer processing, and therefore require a rich, rather than, dumb end-user client (see Figure
4).
Trade-offs.
Integrating a LIMS into the overall IS should take into consideration the company's current infrastructure, long-term plans
for the IS, and investment in hardware and human resources to manage the IS. This decision, in turn, affects the cost of clients
and servers, third-party software needed to connect these LIMS clients, and the resources needed to deploy and upgrade the
LIMS. Furthermore, it affects the robustness and security of the application as a whole as well as the flexibility of the
system to later modification. Depending on the answer and the trade-offs to be made, the organization may decide to use either
a thin-client, web-based, web-enabled, or a thick-client solution.
Network bandwidth.
Thick-clients and web-enabled solutions typically require less network bandwidth. Because thick-clients themselves do much
of the application processing, they do not require an application server for processing. However, it is important to remember
that the database will likely reside at the server level, so communication to and from each thick-client is still required.
Additionally, regional hardware and software is required to operate the cross-platform programs such as Citrix that enable
such networked communication. Web-enabled and some web-based systems offer a hybrid to this approach, depending on where the
functionality resides (i.e., on the client or on the server).
Redundancy.
Thick-clients provide some level of redundancy. In a simple LIMS solution that uses a single thick-client, if the server–network
goes down, the client can still collect sample data and hold it on the PC's hard drive until recovered data can be forwarded
to the appropriate server. In a thin-client application, redundancy is achieved through clustered application servers that
provide load balancing and fail-over, a process that routes client requests to servers within the cluster. If one or more
servers fail, client requests are automatically routed to other servers within the cluster so there is no break in service.
Performance.
Thick-clients tend to have advantages in multimedia-rich applications that would use up a lot of bandwith if fully served.
For example, thick-clients are well suited for chemical drawing and molecular modeling programs, which require a significant
amount of computing power. With that said, new technologies such as AJAX (Asynchronous JavaScript and XML), are offering more
dynamic user experiences than previously available over the web. Moreover, thin-client LIMS can be easily scaled by adding
servers to the cluster.
Access.
With a thin-client LIMS solution, users can access the LIMS from virtually any Internet-ready device. All of the laboratory's
applications and data are maintained centrally, thus allowing any number of people to share them in a secure way by simply
plugging in a thin-client browser. Thin-clients also enable connectivity by critical users external to the laboratory such
as executives, customers, and partners. Moreover, thin-client solutions can leverage a "dumb" client or portable device, as
opposed to some web-based systems that require a client to leverage the .NET framework to communicate with the server. Thick-client
systems pose the most difficulty in enabling enterprise access. Such systems must be installed at each end-user client, and
they have no remote access capabilities. Web-enabled systems offer some remote access, but only to the specific, limited functionality
available via the browser.
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