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Root cause analysis

In this article we will analyze 7 basic tools to identify Root Cause that affect the quality of a software product.

The Seven

1) Process Mapping

Process

It is a set of activities and tasks that transform inputs into products and service delivered to customers

Process maps

Is a diagram depicting activities and tasks, people, systems, inputs, outputs and decisions made in a process?


Looking and Process Maps we will be able to answer questions like: -

1. How long does the process actually take?

2. What steps consume the most time.

3. Where are we seeing defects and why?

4. How can we change the process for improvement?


SIPOC is one of the types of Process Map

  

1. High level map depicting the process on one page.


2. Highest level map

S = Supplier = Who are the internal and external providers of inputs to the process

I = Input = What materials, knowledge or data are provided by the supplier and are needed by the process

P = Process = What are the high levelsteps in 5-7 steps.

O = Output = What products or services are created as result of the process

C = Customer = Who are the internal or external customers of the process

f. Example of SIPOC for making a McDonalds burger

  


Why is SIPOC so important ?

         1) It helps us in defining Process Boundaries.


2) It helps in answering questions like: -

        a. What are the major steps of the process?

                    b. What are the primary process inputs and output?

          c. What are the key customers and suppliers?

When is SIPOC needed ?

  

1) SIPOC is the first tool we should consider using when we are working with a process


2) Use SIPOC to: -

    1. Provide a one-page overview of the process as it is today.

    2. Understand customer input

    3. Who are the suppliers today?

    4. Define the exact of a process.

Tips for building a SIPOC

  

1) As we begin a new project, we define what’s happening in the current situation. Be sure that your SIPOC depicts what is really happening in the process today?


2) Identify the suppliers for inputs


3) Identify all the inputs


4) Identify 5-7 high level steps for the process


5) Verify the flow of information


6) Identify the outputs of the process.

2) Check Sheets

1) Check Sheets is a simple and effective way to collect data to understand our process better.


2) What is a Check Sheet -? 

     i. It is a structure template used to collect data at the location where the data is generated in real-time.

     ii. Operational Definitions - Included in the check sheet are clear and full description of what data is required including unit of measure and when to collect it. This is known as Operational Definitions; this ensures that data is collected in the same way every time.

     iii. When should Check Sheets be used?

          1. Whenever we need to collect data and take observations in the same way     REPEATEDLY 

          2. Check Sheets are a valuable tool for collecting data when it is not available form a system or other pre-existing source 

     iv. Tips for building a Check Sheet

          1. Design the check sheet with the team who are going to use it.

          2. Keep it clear and user friendly.

          3. Include definitions

          4. Include examples

          5. Explain to the team the reason for using checksheets.

          6. Train everyone involved about the checksheet

          7. Validate your check sheet and its data through the use of initial pilot run. Make improvements wherever required.

          8. Do not wait until the end to look at the data.

          9. When collecting data, always be sure to COMMUNICATE.

3) Histogram

     

       a. Histogram is a graphical representation of numerical     data relating to our business process in the form of bars in a chart.


  b. Resembles a bar chart, but a histogram helps us see

i. The central tendencies

ii. The variations in data

  

c. Histograms can be easily built in excel.                

d. The majority of the data will be in the highest      

bar of the histogram.


     

  

Bar Graph uses count data whereas Histogram uses frequency data.


Creating a Histogram in Excel

1) Sort the data column in ascending or descending

2) Create bins/buckets for this data manually.        

3) Create a column called Frequency and manually 

enter the number of occurrences 

4) Insert > Recommended Charts > Histogram.    


When should a histogram be used ?

  

  • When you have to do analysis of numeric data.
  • Some examples are when measuring weight, money, weight, height, age, etc
  • Histogram is very useful when you have a large dataset.
  • Helps communicate the most frequently occurring datasets and the variation being experienced.
  • When you want to showcase summary of your data before and after improvements.

Tips for building your histogram

  

  • A histogram is only suitable for numeric data.
  • Best practice is to have 30 or more datapoints.


4) Pareto Charts

Importance of Pareto Charts

  • Helps understands significant potential root causes
  • Enables Prioritization of what should be handled first (e.g., which are the top categories of defects)

When should Pareto charts be used?

When analyzing Frequency data - relating to Problems, Causes or Categories in a process.

  • e.g., count of defects of different categories
  • e.g., count of customers in different regions

Creating a Pareto Chart

  • Gather your data
  • Sort data in descending order
  • Calculate cumulative percentages.
  • Create Pareto chart and identify the top 20% causes which contribute to 80% of the issues.


5) Fishbone Diagram / Cause & Effect Diagram / Ishikawa Diagram

   Creating a Fishbone Diagram


It is a two-step process to create a Fishbone Diagram

1) Brainstorming                                                       

     a. Call all the SMEs (Subject Matter Experts)        

in one conference room.

 b. As a Facilitator - Tell them that they have     

to analyze the root cause of the problem.

c. List all the causes given by the SMEs.     

d. Categorize the above root causes in a spreadsheet 

according to 5 Ms

   i. Man

   ii. Machine

   iii. Mother nature

   iv. Material

   v. Method          


Creating the Fishbone diagram

  • Put the above root causes in a Fishbone diagram. 


  • The 5 M’s become the five fins of the fishbone diagram


  


Importance of Fishbone Diagram


  1. Shows the Cause-And-Effect of a problem in one diagram.


    2. Helps structure a brainstorming session



When should a Fishbone diagram be used?


When you want to identify the possible Root Causes of a problem (after data relating to the problem has been collected).






Next - 5 Why Analysis and Run Charts

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