Installation Methods

For each high- and medium-priority application, you must determine the best way to install it. For each, consider the following:

• Automatic installation Most applications provide a way to install automatically. For example, if the application is a Windows Installer package file (with the .msi file extension), you can install the application automatically. The section titled "Automating Installation" later in this tutorial describes how to install applications packaged with common technologies automatically. In this case, you don't need to repackage the application unless you want to deploy a configuration that isn't possible otherwise.
• Repackaged application If an application does not provide a way to install automatically, you can repackage it to automate and customize installation by using one of the packaging technologies described in the section titled "Repackaging Legacy Applications" later in this tutorial. Repackaging applications is a complex process and is quite often the most costly and tedious part of any deployment project. Make the decision to repackage applications only after exhausting other possibilities. Doing so requires technical experience with repackaging applications or using third-party companies to repackage the application for you.
• Screen scraping You can automate most applications with interactive installers by using a tool that simulates keystrokes, such as Windows Script Host. (See the section titled "Windows Script Host" later in this tutorial for more information.) Understand that this method is more of a hack than a polished solution, but sometimes you're left with no other choice. Occasionally, the installation procedure may require the user to use the mouse or otherwise perform some complex task that cannot be automated easily. In these circumstances, automating the installation process may not be feasible.

For each application, record the installation method. Does the application already support automated installation? If so, record the command required to install the application. Are you required to repackage the application? If so, record the packaging technology you'll use and the command required to install the application. If you will use screen scraping to install the application, indicate that decision in the application inventory.