Problems and exercises
Study the E-R diagram of Figure 7–20. Based on this E-R diagram, answer the following questions
a. How many EMPLOYEES can work on a project?
One to many – many employees can work on one project
b. What is the degree of the Used on relationship?
Binary, two degrees for the relationship.
c. Do any associative entities appear in this diagram? If so, name them.
There are no associative entities directly reflected by the associative entity. Works on, which is a many-to-many relationship, lacks attributes thus do not required to be reflected as an associative entity.
d. How else could the attribute Skill be modeled?
The attribute Skill can be remodeled as weak entity.
e. What attributes might be attached to the Works_on relationship?
Different positions on the project as well as jobs and requirements.
f. Could TOOL be modeled as an associative entity? Why or why not?
No. different tools can be utilized on different tasks. Either more or less tools can be required depending on the tasks at hand.
16. The owner of two pizza parlors located in adjacent towns wants to computerize and integrate sales transactions and inventory management within and between both stores. The point-of-sale component must be very easy to use and flexible enough to accommodate a variety of pricing strategies and coupons. The inventory management, which will be linked to the point-of-sale component, must also be easy to use and fast. The systems at each store need to be linked so that sales and inventory levels can be determined instantly for each store and for both stores combined. The owner can allocate $40,000 for hardware and $20,000 for software and must have the new system operational in three months. Training must be very short and easy. Briefly describe three alternative systems for this situation and explain how each would meet the requirements and constraints. Are the requirements and constraints realistic? Why or why not? (5 points)
Alternative A – Purchase the prepackaged or the off-the-shelf systems. Not a good idea given that POS companies have own proprietary software they use.
Alternative B – If the company requires an information system but lacksk the expertise or personnel to develop it in-house and a appropriate off-the-shelf system is unavailable, the company would most likely seek the services of an information technology (IT) firm. Alternative B is is better. The project manager will hire a POS company to install the information system to enable easy connection of the two locations. The company would get an IT team in place and use their server for backup. The current amount of $60.000 is sufficient to hire the best information system in the market.
. C .In-house development Hybrid solutions including some in-house and other purchased software components are usually common.
17. Compare the alternative systems from Problem and Exercise 16 using the weighted approach demrelatively small system? Why or why not? (5 points)
Alternative B is the Highest. It is therefore recommend to the board.
