IENG 451 / 452 Data Collection: 7 Tools of Ishikawa IENG 451 - Lecture 09 Data Collection: 7 Tools of Ishikawa 5/27/2018 IENG 451 Operational Strategies (c) 2016 D.H. Jensen

Ishikawa’s “Magnificent Seven” Tools The Seven Tools are: Histogram / Stem & Leaf Diagram Pareto Chart Cause & Effect (Fishbone) Diagram Defect Concentration Diagram Check Sheet Scatter (Plot) Diagram Control Chart - not covered in this course! The tools were not invented by Ishikawa, but were very successfully put into methodical use by him The first six are used before starting to use the seventh They are also reused when needed to find an assignable cause 5/27/2018 IENG 451 Operational Strategies

Ishikawa’s Tools: Histogram A histogram is a bar chart that takes the shape of the distribution of the data. The process for creating a histogram depends on the purpose for making the histogram. One purpose of a histogram is to see the shape of a distribution. To do this, we would like to have as much data as possible, and use a fine resolution. A second purpose of a histogram is to observe the frequency with which a class of problems occurs. The resolution is controlled by the number of problem classes. 5/27/2018 IENG 451 Operational Strategies

Histogram: Stem-and-Leaf Plot ENGM 720: Statistical Process Control Histogram: Stem-and-Leaf Plot 48 53 49 52 51 63 60 64 59 54 47 45 79 65 62 Divide each number into: Stem – one or more of the leading digits Leaf – remaining digits (may be ordered) Choose between 4 and 20 stems Example: 4| 5| 6| 7| 8 9 7 9 5 3 2 1 2 3 4 9 3 4 4 2 5 9 Done! 5/27/2018 IENG 451 Operational Strategies (c) 2002-2006 D.H. Jensen & R.C. Wurl

Histogram Example (Excel) 5/27/2018 IENG 451 Operational Strategies

Ishikawa’s Tools: Pareto Chart 80% of any problem is the result of 20% of the potential causes Histogram categories are sorted by the magnitude of the bar A line graph is overlaid, and depicts the cumulative proportion of defects Quickly identifies where to focus efforts 5/27/2018 IENG 451 Operational Strategies

Ishikawa’s Tools: Fishbone Diagram Cause & Effect diagram constructed by brainstorming Identified problem at the “head” Connects potential causes along the spine Sub-causes are listed along the major “bones” Man Material Method Machine Environment 5/27/2018 IENG 451 Operational Strategies

Cause & Effect Diagram, Cont. The purpose of the cause and effect diagram is to obtain as many potential influencers of a process, so that the problem solving can take a more directed approach. Material Machine Man Method Environment Skill Level Low RPM Orifice Clogs Dusty Humidity Poor Conductor Attention Level Poor Mixing Travel Limits Temperature Worn Parts Poor Vendor Bad Paint 5/27/2018 IENG 451 Operational Strategies

Ishikawa’s Tools: Defect Concentration Diagram A defect concentration diagram graphically records the frequency of a defect with respect to product location. Obtain a digital photo or multi-view part print showing all product faces. Operator tallies the number and location of defects as they occur on the diagram. 5/27/2018 IENG 451 Operational Strategies

Ishikawa’s Tools: Check Sheet Title Header Info: Date, Time, Location, Operator, etc. List of Prob Types Times of Problem Occurrence (periodic) Statistics For Prob Types Time of Occurrence Statistics Overall Statistics Instructions, settings, comments, etc. Raw Data recorded here Check sheets are used to collect data (values or pieces of information) in a consistent manner. List each of the known / possible problems Record each occurrence including time-orientation. 5/27/2018 IENG 451 Operational Strategies

Ishikawa’s Tools: Scatter Plot A scatter plot shows the relationship between any two variables of interest: Plot one variable along the X-axis and the other along the Y-axis The presence of a relationship can be inferred or ruled out, but it cannot determine if a cause and effect relationship exists Y X 5/27/2018 IENG 451 Operational Strategies

VSM Lab Assignment Due THU IENG 451 / 452 VSM Lab Assignment Due THU Create an AS-IS and a TO-BE Value Stream Map for producing a homemade pizza: Starting point is deciding what goes on the pizza Ending point is when you start to chew on the pizza AS-IS map represents 1st cut process, and includes: Process steps AND information flows Appropriate symbols AND process data Include storage space and material handling times, etc. TO-BE map represents improvements from 1st cut Document this in a similar fashion, on a separate map! Include Value-Analysis / Time Value Map on bottom of both Non-Value Added to Value Added time ratio (BNVA + NVA) VA 5/27/2018 IENG 451 Operational Strategies (c) 2016 D.H. Jensen

IENG 451 Operational Strategies Questions & Issues 5/27/2018 IENG 451 Operational Strategies (c) 2016 D.H. Jensen