ماهو الافضل أن يكون النظام على شكل موقع إلكتروني (web Application) أو برنامج عادي (windows Application)

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السلام عليكم ورحمة الله وبركاته

إخواني وأخواتي أعضاء هذا المنتدى

في البداية أحب أن اشكركم على هذا الجهد الرائع الذي بذلتموه في هذا المنتدى والفائدة العظيمة التي نجنتيها جميعنا من من المواضيع المميزة والرائعة

وأحب ان أطرح تساؤلا وهو :

عند بناء نظام إلكتروني لشركة ما (نظام لإدارة الشركة) ماهو الافضل أن يكون على شكل موقع إلكتروني (web Application) أو برنامج عادي (windows Application)

مع العلم أن الشركة لا تمانع أيا كان نوعة ولكن أريد عمل دراسة مبسطة عن الافضل لكي يستفيد منها الجميع فما هي المعايير والشروط التي من خلالها نحدد نوع التطبيق المستخدم.

ولكم جزيل الشكر والعرفان

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[Amgad]

السلام عليكم

اليك المشاركة السابقة بالمنتدى للأخ / أحمد الجابري

إضغط هنا : :لماذا WEB APPLICATIONS, مقاله نظرية لفائدة هذه التقنية

إضغط هنا Web Based & Web Enabled

Web applications vs Client-Server Applications
In this article I discuss the differences between thin (web-based) clients and thick (desktop) clients, and attempt to help
answer an often asked question: "Should this business system we want to develop be a web-application?"

Web applications, sometimes called "thin client" solutions, are concerned with performing business tasks through a web
interface. Usually, this involves viewing and manipulating data in a database.



They are typically deployed on an intranet or extranet, with access restricted by passwords or other methods.



Client-Server applications, or "Thick Client" solutions, are the more traditional way of doing things. The "server" side
often has a "middle layer" inbetween the client and the database, this is called a "3-tier" solution. Sometimes there are
multiple middle layers which interract, and this is called an "n-tier" solution. Sometimes there are thin-clients and thickclients
interracting with the same back-end systems.



Larger systems will sometimes have a combination of thin-client and thick-client front-ends which interract with various
bits of "middleware" that in turn interract with one or more databases.



In this article I will ignore the server side and focus on the differences between thin (web-based) clients and thick
(desktop) clients, and I will attempt to help answer a question often asked "Should this business system we want to
develop be a web-application?"



h2. Points to consider:



h3. Flexibility in interface design



How often witll the users be using the system? Essentially the more the system gets used and the more complex the
tasks the greater opportunity to take advantage of the richer set of controls available in a thick-client.



Modern browsers allow for a much richer range of interraction than was possible previously, but it's still a lot easier to
design a good user interface using a desktop application design system. It simply takes a lot of javacript to acheive
some of what is easy in a visual development enviromnent like VB or Delphi.



There are a much larger collection of components available for

Precise positioning of controls/windows, sizing of fonts, etc, is a little easier with a desktop app.



It's much easier to do realtime screen updates with a desktop app. For instance updating a view of matching records
from a "find" field in realtime - an invaluable feature in Mozilla's mail applications.

Slider bars, gauges, pop-up calendars, extensive-menuing, dockable-windows, tree-widgets, etc, are easier to implement
on a thick-client.



Many of these can be done with ActiveX or Java based controls for a web app, but it requires more time and effort than a
desktop app, and the result tends to be "clunkier".



h3. Reports

* Do your reports have complex printing requirements? (eg multiple printers, multiple sizes, landscape vs portrait,
controlled pagination) These are considerably more diffcult to handle with a web-application.



h3. Usage

# How many hours/minutes will staff spend using this application every week?

* The more time spent in the application, the more likely it's worth going to the extra level of customization offered by a
desktop app.



Deployment Issues



# How distributed are your staff?

# How many of them are there?

# Are they technically literate? Would you trust them to update a thick-client on their own?

* Web applications do not need to be installed and upgraded across many PC's, saving time and hassle.

* Thick client software can include the ability to self-update over the internet. This is not trivial to implement, however,
and may cause unpredictable problems on some computers.

* If the software is likely to be regularly updated, web-applications or self-updating thick clients will save a lot of time.



h3. Do your staff all use the same operating system?



* Multiple operating systems make problems for desktop apps just as multiple browser types make problems for webapplications.
Differences between windows versions can usually be handled, differences between Windows, Mac, and
Unix usually require considerable effort to handle!



* Writing a desktop app that works on windows and macs more or less requires using Java, and it's difficult to make the
interface comfortable to either, let alone both. In some cases writing one client for each may be a better solution.

* Microsoft's .NET platform may also work on multiple O/S's in the future but will have it's own pitfalls.



* The usual hurdle that has to be faced is writing for different versions of windows - many old applications do not work
well on Microsoft XP, and applications written for NT/2000/XP sometimes have trouble running on Win9x/ME



h3. Do your staff all use the same web browser?



* I don't recommend attempting to deploy web-applications if the users are using Netscape 4.x or IE3.x, but if anyone is
still using these browsers upgrading them should be a priority as half the web is probably looking broken right now.

* These days no one would consider writing a web-application for Netscape 4.x, it has too many bugs in it's dynamic html
engine, and it is not at all standards-compliant. Writing for IE4+ or IE5+ has fewer pitfalls.

Netscape 6/7 and Mozilla 1.x are broadly compatible with IE5+ but there will be a few small issues to sort out.

* Do note that IE for Mac is a different browser to IE for Windows from the point of view of a web application.



Do your staff always work at the same PC or do they move around?



* Web applications have the advantage of being available from anywhere, and any personalisation features are available
from wherever the user is.

* But web applications will sometimes run into trouble if the web-browser is not configured properly for the application -
this problem can be minimised if the web application is designed to run in multiple environments.



h3. Security Issues



* Web applications that may be used in a shared enviroment obviously have security implications. For instance many
browsers allow you to save passwords, and if this is done subsequent users of the browser may find they can access the
application.



h3. Key points



h4. Key Advantages for Client-Server Applications

* Flexibility in interface design

* Speed in execution



h4. Key Advantages for Web Applications

* Ease of deployment

* Ease of software updates



h3. How to get the best of both worlds?



Don't put all your eggs in one basket. Deploy smaller applications that accomplish different tasks, eg data-entry, dataanalysis,
and reporting. Look at the specifics of each task, and see whether a web-application is more suitable. However
this may involve using multiple solution providers, which has it's own pitfalls. If you can find a company that has abilities
in both toolsets, they may well suggest such a hybrid themselves.



h4. Key points if using a hybrid approach:

* Store all your data in one location to avoid the hassles of duplication, inconsistency, and double-entry.

* Use a client-server database. File based databases are inadequate for multiple access applications and will usually just
lead to grief.



h4. "Rich" Web Applications



Java - Embedding Java Applets into a web pages allows one to add fancier functionality at the cost of increased
download time and reduced compatibility. In some csaes it's absolutely appropriate.



XUL - This is a widget toolset built into Mozilla based web browsers. I've never tried it, but potentially this will give you all
the advantages of DHTML applications with a but with a much larger set of controls. You'll need to find an experienced
developer, and your userbased will need to be standardised on a Mozilla client - I recommend
"Firefox":http://www.mozilla.org/products/firefox/

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