Metin Atmaca - 030080007, 1st week definitions

     

1. Affinity Diagram (Organization- Management)

Previous Definition:

The purpose of affinity diagram is to organize large groups of information to meaningful categories. The affinity diagram helps break old patterns of thought, reveal new patterns, and generates more creative ways of thinking. The affinity diagram helps organize team's thoughts most effectively when:the issues seem to large and complex;you need to break out of old,traditional ways of thinking; everything seems caotic; or there are many customer requirements. The affinity diagram helps tonaturally group ideas or your customer's valid requirements and showthe relationship between items and groups. The affinity diagram helps you gather and group large amounts of language (e.g., needs, wants, wishes, ideas, amd opinions) into natural relationships.

(Soleimannejed F., Six Sigma, Basic Steps & Implementation , p. 94)

New Definition (Better):

The affinity diagram organizes a large number of ideas into their natural relationships. This method taps a team’s creativity and intuition. It was created in the 1960s by Japanese anthropologist Jiro Kawakita.

When to Use an Affinity Diagram

·        When you are confronted with many facts or ideas in apparent chaos

·        When issues seem too large and complex to grasp

·        When group consensus is necessary

Typical situations are:

·        After a brainstorming exercise

·        When analyzing verbal data, such as survey results.

Affinity Diagram Procedure

Materials needed: sticky notes or cards, marking pens, large work surface (wall, table, or floor).

1.    Record each idea with a marking pen on a separate sticky note or card. (During a brainstorming session, write directly onto sticky notes or cards if you suspect you will be following the brainstorm with an affinity diagram.) Randomly spread notes on a large work surface so all notes are visible to everyone. The entire team gathers around the notes and participates in the next steps.

2.    It is very important that no one talk during this step. Look for ideas that seem to be related in some way. Place them side by side. Repeat until all notes are grouped. It’s okay to have “loners” that don’t seem to fit a group. It’s all right to move a note someone else has already moved. If a note seems to belong in two groups, make a second note.

3.    You can talk now. Participants can discuss the shape of the chart, any surprising patterns, and especially reasons for moving controversial notes. A few more changes may be made. When ideas are grouped, select a heading for each group. Look for a note in each grouping that captures the meaning of the group. Place it at the top of the group. If there is no such note, write one. Often it is useful to write or highlight this note in a different color.

4.    Combine groups into “supergroups” if appropriate.

Affinity Diagram Example

The ZZ-400 manufacturing team used an affinity diagram to organize its list of potential performance indicators. Figure 1 shows the list team members brainstormed. Because the team works a shift schedule and members could not meet to do the affinity diagram together, they modified the procedure.

Figure 1 Brainstorming for Affinity Diagram Example

They wrote each idea on a sticky note and put all the notes randomly on a rarely used door. Over several days, everyone reviewed the notes in their spare time and moved the notes into related groups. Some people reviewed the evolving pattern several times. After a few days, the natural grouping shown in figure 2 had emerged.

Notice that one of the notes, “Safety,” has become part of the heading for its group. The rest of the headings were added after the grouping emerged. Five broad areas of performance were identified: product quality, equipment maintenance, manufacturing cost, production volume, and safety and environmental.

Figure 2 Affinity Diagram Example

 (Nancy R. Tague, The Quality Toolbox, Second Edition, p. 96.)

2. Computer-Aided Process Planning (CAPP) (Manufacturing)

Previous Definition (Better):

Process planning is concerned with selecting methods of production: tooling, fixtures, machinery, sequence of operations and assembly. All of these diverse activities must be planned, which traditionally has been done by process planners.

When done manually, this task is highly labor-intensive and time-consuming and relies heavily on the experience of the process planner. Computer-Aided Process Planning (CAPP) accomplishes this complex task by viewing the total operation as an integrated system, so that the individual steps involved in making each part are coordinated with others anda re performed efficiently and reliably.

(manufacturing engineering and technology-Serope kalpakjian, page 1204-1205)

New Definition:

An efficient CAPP system has a key role to integrate the design and manufacturing or assembly systems properly considering available resources and design constraints. It has been found that 15% of the process planner’s time is spent on technical decision making  while  remaining time is spent equally between gathering data, calculating and the preparation of documentation. Investigation shows that an efficient CAPP systems could result in a total reduction of the manufacturing cost by up to 30% and time in the manufacturing cycle and the   total engineering time could also be reduced by up to 50%.

(Younis, M.A. and Wahab, A.M.A., 1997,”A CAPP Expert System for rotational components”, Computers and Industrial Engineering, pp. 509-512)

3. Net-Shape Manufacturing (Manufacturing Process)

Previous Definition:

A particular manufacturing process may not produce a finished part, and thus additional operations may be necessary. For example, a forged part may not have the desired dimensions or surface finish; as a result, additional operations such as machining or grinding may be necessary. Likewise, it may be difficult, impossible, or uneconomical to produce a part with holes in it by using single manufacturing process, and thus a subsequent process may be required, suc as drilling or producing the hole using various advanced methods, such as chemical pr electrical means. Furthermore, the holes produced by a particular manufacturing processs may not have the proper roundness, dimensional accuracy, or surface finish, and thus they may require an additional operation, such as honing.

(Kalpakjian S., Schmid S.R.,Manufacturing Engineering and Technology, 5th Edition, pg.31

New Definition (Better):

The formation of strong, dense metal parts is the goal of many innovative approaches to three-dimensional manufacturing and repair of advanced components and structures. Laser rapid prototyping of complex shapes and designs has been in use since the 1980’s. This includes stereolithography, selective laser sintering, and mold-shape deposition casting. However, these processes have largely been limited to nonmetallic. In the last ten years or so, several companies in the United States and abroad have focused on techniques of metal powder fusion to provide dense metal parts.

(Joshua Rabinovich, Advanced Materials & Processes, Volume 161, Issue 1, January 2003 (ASM International) p. 47)

4. Ball Milling (Manufacturing):

Previous Definition (Better):

The ball mills can be divided into 2 types : centrifugal and planetary mills.
In a centrifugal ball mill, a single bowl fastener is merely horizontally and eccentrically driven while not rotating itself.In spite of this, the velocity of the grinding balls in this case is still six times that of the grinding balls in the gravity ball mills.
In planetary ball mills 2 or 4 bowl fasteners ,each of which accommodates one grinding bowls and supporting disc rotate in opposite directions, so that 2 different centrifugal forces act on the bowl contents.
(Powder metallurgy technology first edition 2002 p.34)

New Definiton:

Ball mills, which use steel or ceramic balls, are mainly used for fine grinding and are divided into two types:

-          Tube mills, which usually have a high length: diameter ratio (~6:1) and two compartments separated by a partition

-          Single-compartment mills, which have a small length: diameter ratio (~1.5:1). Single-compartment ball mills are the best-known form of tumbling mills.

(Alban J. Lynch, Chester, A. Rowland, The history of grinding, p. 95)

5. Visual sensing (Manufacturing):

Previous Definition:

In visual sensing, cameras optically sense the presence and shape of the object. A microprocessor then processes the image (usually in less than one second), the image is measured, and the measurements are digitized (image recognition). There are two basic systems of machine vision: linear array and matrix array.

(Kalpakjian S., Schmid S.R.,Manufacturing engineering and technology, 5th Edition, p 1173)

New Definition (Better):

Industrial robots are designed for tasks as pick and place, welding, grinding, parts assembly and painting, where repeated work is needed and the robot path is programmed previously. Consequently, if the working condition is changed and deviates from the programmed parameters, the robot may not be able to function properly. To ensure that the robot adapts to new tasks without reprogramming, sensing technology is integrated to the robot system to enhance the robot’s capability to work in a dynamic environment. It makes the robot system easy-to-use for the end user and yet operative with a human. Vision sensing is a vital sensing technology where the robot mimics human vision to guide itself through the complex process.

(Zhongxue Gan, QingTang, Visual Sensing and its Applications, preface)