Limitations of E-R Model

Before in the assignment for my class (ISYS 464 Enterprise Data Management), my group saw how the asset could be a support contract, software, and hardware, which all have unique characteristics and many similar characteristics.  Each asset is assigned to a user (operator), supported by some IT staff, and purchased (owned) by some manager.  To represent this in traditional ER model, it would have to look like this.

The ER Model cannot distinguish between different types of objects that share qualities, but differ slightly. We decided there must be a better way...

Asset Management Application: E-R Model

In one project for a class (ISYS 464 Enterprise Data Management), I created a small asset management application that could be used for information technology support group to track the assets such as software, hardware, and support contracts.  These would store the order information and reseller information, in case this needed to be referenced (such as a return or getting service).

Here's a simple Entity-Relationship model.

The crazy part of this is that the asset can be three different types of assets: support contracts, software, and hardware.  The support contract can support a software asset or a hardware asset.

The asset itself can be assigned to a user, managed by support, and purchased (owned) by a manager, all of which are some type of employee.  There's not distinction in the type of employee, other than has the asset relates to the employee (owner, user, supporter).

So the question is how can this be easily represented?

Purple Screen of Death

So I tried again to get VMWare ESXi running on my small Shuttle, this time with ESXi 4.0 upgrade 1, but alas, I got the purple screen of death:

ESXi vs. Shuttle X27D

School is out, so now the real learning must begin.  I thought of taking VMWare ESXi out for a stroll, and put this on the sexy petite Shuttle X27D.  But alas, I can't get no satisfaction.  Grrr.

I'm stuck with the error:  Failed to load lvmdriver.

I'm guessing that the problem is that I am using an external USB cd-rom player.  I will try to scavenge an internal slim cd-rom player from another system.