Ozan Kovancı 1st Week Missing Terms

1-FMEA (Failure Mode & Effect Analysis)

Failure mode and effect analysis (FMEA) is an important technique that is widely used in industry, including the big three auto manufacturers for continuous product quality improvement to satisfy the needs of the customer. FMEA can be described as a systemized group of activities intended to:

- Recognize and evaluate the potential failure of a product/process and its effects

- Identify actions that could eliminate or reduce the chance of potential failure occuring

- Document the process

To implement FMEA, the following steps may be taken:

a- Identify problems.

b- Use flow process charts for understanding the problem.

c- Collect data.

d- Prioritize the problems to be studied. The ranking of priorities is based on the following:

RPN (risk priority number) = occurence x severity x detection

- Occurence: how often the failure occurs

- Severity: how serious the failure is

- Detection: how easy or difficult it is to detect the failure.

e- Use appropriate tools to analyze the problem.

f- Implement the suggestions.

g- Confirm and evaluate results

h- Repeat FMEA periodically.

[Nanua Singh; Systems approach to computer-integrated design and

manufacturing,1996 ; pages 368-369-370]

7- OSI (Open System Interconnection)

The open system interconnection (OSI) reference model proposed by the International Standard Organization (ISO) provides a framework for modeling communication protocols. This permits interoperability between dissimiliar systems. The ISO/OSI model divides the communication process into seven layers: the phsical layer, the data link layer, the network layer, the transport layer, the session layer, the presentation layer and the application layer.

[Nanua Singh; Systems approach to computer-integrated design and

manufacturing,1996 ; page 587]

8- Continuous Path Tool Motion

Continuous-path motion (also referred to as contouring) involves precise control of the path followed by the tool as it goes through the required motion.

In order to achieve this control over the tool motion, APT uses three control surfaces referred to as the drive surface, part surface, check surface. During contouring, all three surfaces must be defined explicitly or implicitly. The cutting tool is required to maintain continuous contact with the drive surface as well as the part surface. The part surface controls motion along the tool axis and tip of the tool maintains contact with the part surface. Therefore, the part surface determines how deep the tool cuts into the workpiece. The check surface is used to to indicate where the current tool motion stops (which is also where the next tool motion will start) The drive surface must always be given explicitly during a contouring motion, whereas the other surfaces may be given implicitly.

[Nanua Singh; Systems approach to computer-integrated design and

manufacturing,1996 ; pages 227-228]