Analyse Phase:
Phase Learnings:
The key Focus of the Analyse phase is to fully review the defined problem and to research into the root causes of the part defect. This is essentially started by completing a Brainstorming session.
This step in the process is the most crucial step and it is paramount to ensure that you have the right people present in the Brainstorming sessions and the subsequent Cause and Effect Rating phase.
To this effect we included the Process Engineer, Development Engineer, Operator, Engineering Manager and Tool Supplier within the Brainstorming process.
Without this inclusive Brainstorming session the Analyse phase would not have been as robust as required to identify all the potential Defect Causes. This for me is the number 1 key learning of the Phase
To document this brainstorming session we utilised the Ishikawa Diagram.
The other tools that are then used in the phase contribute in different ways to the phase outputs but essentially at the end of the phase we have a list of prioritised tasks based on the Cause and Effect Prioritisation Matrix and the FMEA sheet,
Once the brain storming sessions were compiled in the Ishikawa Diagram each potential root cause was rated and this rating was utilised to identify the main areas to focus on. We achieved this by using a Cause and Effect (C&E) Prioritisation Matrix and a FMEA for the process.
The C&E Matrix defines the priority of Inputs to Outputs and helps define which inputs to focus on.
The FMEA contained the specific causes that were linked to the defect based off the Brainstorming.
Once this was completed we had a clear tasks to focus on for the Improve Phase.
The other key phase learning was to ensure that when a cause was identified in the brainstorming session that it was fully understood. This was attained by adopting a 5 Why's approach to each cause. (Examples of this approach can be seen in the Method Example below)
This approach has resulted in a clearly define list of Causes and has helped to highlight the areas for improvement within the process.
Tools Used:
Ishikawa Diagram
The Ishikawa Diagram is often referred to as the cause and effect or fish-bone diagram. This Tool focuses on the potential causes of the defect on the parts and splits them into 6 Main Categories: Man, Method, Machine, Materials, Measure, Mother Nature.
Categorization is crucial to ensure correct root cause is tackled.
Man: This category covers causes related to the person interaction with the process: eg operator error at setup where setup procedure was fully defined but not followed correctly.
Method: This category relates to the way/system in place to allow the process to run. eg. Setup instructions are not fully defined leading to the operator setting up the process incorrectly. This is due to incorrect 'Method' and not 'Man' ( A 5 Why approach was used here to distill this cause to Method vs Man as when reviewed the operator set the process as instructed but the setup process was not correctly defined)
Machine: This category covers the equipment used within the process. eg. Machine Axis accuracy is not correct for process tolerances required.
Materials: This category covers the material inputs to the process, eg incoming raw material out of specification to defined specification.
Measure: This category covers the potential errors due to incorrect measures: eg Vernier Calipers used to measure a feature where a micrometer is defined as the required measurement method for the feature.
Mother Nature: This category covers all other events that could effect the process.
eg. Sunlight levels shining into a process area at different times of the day or through-out the year can for example effect vision system lighting. These type of causes are usually attributed to issues that occur sporadically or cyclically within a process. Typically these type of causes are a last port of call for investigation but it is important to be mindful of the effect of mother nature on processes however remote that may seem.
Once the Brainstorming was completed for our project the Causes were assessed and entered into the template to aid visualization of the causes.
.
C&E Prioritisation Matrix:
From the causes defined in the Ishikawa Diagram the Causes were distilled further into Concise Inputs and Outputs of the process.
Each point on the process is rated with regards to the effect of that point on importance to the customer. This allows for ratings that affect the quality of the final goods to be higher rated than say point that merely provide financial benefits.
The intention of the matrix is to rank the inputs vs the outputs in order to show the inputs that have the greatest impact on the outputs.
In larger projects this matrix would be utilised to reduce the amount of inputs to be assessed in a DOE or trials based on the weighted score.
Outputs:
Hole refers to both the presence of a hole and the non presence of a hole
Burr refers to presence of a burr or no presence of a burr.
Tool life refers to the tool life of the drill.
Each output is Rated for importance to the end user. For the example below the presence of a hole is the most important factor so rated with a 9, the tool life is rated as a 3 as it will only result in a cost of manufacture increase but essentially will not affect the end product to the customer.
The input variables cover causes highlighted in the Fishbone Diagram
The intention of the matrix is to rank the inputs vs the outputs in order to show the inputs that have the greatest impact on the outputs.
In larger projects this matrix would be utilised to reduce the amount of inputs to be assessed in a DOE or trials based on the weighted score.
Failure Mode Effect Analysis:
A failure mode effect analysis has been completed on the process to further aid the assessment the impact of failure modes on the Process based off the RPN Number for the process.
The excerpt from the FMEA below shows the headings that are assessed within an FMEA.
These are then assessed based on Severity, Occurance and Detection.
Col. 1 Input: eg Micro Drilling
Col. 2 Potential Failure mode: eg Drill Damage During Installation
Col. 3 Effect of the Failure mode: eg Incomplete or Complete Hole with Burr
Col, 4 Severity of this Effect. Severity of 8 is assigned both of these.
Col. 5 Potential cause. eg Drill tip damaged by hitting off the bar within the machine during setup of the tool length.
Col. 6 Potential of the occurance: 3
Col. 7 Current process controls: eg 100% Visual Inspection
Col. 8 Detection Rate: 1
Col. 9 RPN is the Risk Priority Number for the Failure mode.
Col. 10 Actions required: Eg trial on drill to see if this step could cause drill failure
Col. 11 Owner of Action.
Col. 12 Actions Taken
Col 13-16 RPN after actions completed.
The Severity, Occurrence and Detection rates are defined within standard tables that rate them based on the impact.
Severity assesses the impact of the Failure mode from 1 - 10 with 1 having no effect and 10 resulting in a failure mode that could happen without warning or endanger an operator. For our project example below a rating of 8 is assigned as it will disrupt the production line and part are scrapped if the defect is present.
Occurance is assessed vs failure rate or process Cpk. This rating can be difficult to define as it typically will be based on opinion vs facts. Where historical facts are available these should be utilised. A rating of 1 reflects an occurance of 1 in 1,500,000 and a rankingof 10 reflects a rate of 1 in 2., For this example a rate of 3 is specified as it is believe that the failure mode would be an isolated mode of failure but may happen if not addressed.
Detection is based on the ability of the process to detect the failure mode. 1 refers to a process where detection is almost certain. A rating of 10 reflect where detection is almost impossible, For this example a detection rate of 1 is selected as we have 100% inspection for this defect.
This step in the process is the most crucial step and it is paramount to ensure that you have the right people present in the Brainstorming sessions and the subsequent Cause and Effect Rating phase.
To this effect we included the Process Engineer, Development Engineer, Operator, Engineering Manager and Tool Supplier within the Brainstorming process.
Without this inclusive Brainstorming session the Analyse phase would not have been as robust as required to identify all the potential Defect Causes. This for me is the number 1 key learning of the Phase
To document this brainstorming session we utilised the Ishikawa Diagram.
The other tools that are then used in the phase contribute in different ways to the phase outputs but essentially at the end of the phase we have a list of prioritised tasks based on the Cause and Effect Prioritisation Matrix and the FMEA sheet,
Once the brain storming sessions were compiled in the Ishikawa Diagram each potential root cause was rated and this rating was utilised to identify the main areas to focus on. We achieved this by using a Cause and Effect (C&E) Prioritisation Matrix and a FMEA for the process.
The C&E Matrix defines the priority of Inputs to Outputs and helps define which inputs to focus on.
The FMEA contained the specific causes that were linked to the defect based off the Brainstorming.
Once this was completed we had a clear tasks to focus on for the Improve Phase.
The other key phase learning was to ensure that when a cause was identified in the brainstorming session that it was fully understood. This was attained by adopting a 5 Why's approach to each cause. (Examples of this approach can be seen in the Method Example below)
This approach has resulted in a clearly define list of Causes and has helped to highlight the areas for improvement within the process.
Tools Used:
Ishikawa Diagram
The Ishikawa Diagram is often referred to as the cause and effect or fish-bone diagram. This Tool focuses on the potential causes of the defect on the parts and splits them into 6 Main Categories: Man, Method, Machine, Materials, Measure, Mother Nature.
Categorization is crucial to ensure correct root cause is tackled.
Man: This category covers causes related to the person interaction with the process: eg operator error at setup where setup procedure was fully defined but not followed correctly.
Method: This category relates to the way/system in place to allow the process to run. eg. Setup instructions are not fully defined leading to the operator setting up the process incorrectly. This is due to incorrect 'Method' and not 'Man' ( A 5 Why approach was used here to distill this cause to Method vs Man as when reviewed the operator set the process as instructed but the setup process was not correctly defined)
Machine: This category covers the equipment used within the process. eg. Machine Axis accuracy is not correct for process tolerances required.
Materials: This category covers the material inputs to the process, eg incoming raw material out of specification to defined specification.
Measure: This category covers the potential errors due to incorrect measures: eg Vernier Calipers used to measure a feature where a micrometer is defined as the required measurement method for the feature.
Mother Nature: This category covers all other events that could effect the process.
eg. Sunlight levels shining into a process area at different times of the day or through-out the year can for example effect vision system lighting. These type of causes are usually attributed to issues that occur sporadically or cyclically within a process. Typically these type of causes are a last port of call for investigation but it is important to be mindful of the effect of mother nature on processes however remote that may seem.
Once the Brainstorming was completed for our project the Causes were assessed and entered into the template to aid visualization of the causes.
.
 |
| Ishikawa Diagram: Cause and Effects |
C&E Prioritisation Matrix:
From the causes defined in the Ishikawa Diagram the Causes were distilled further into Concise Inputs and Outputs of the process.
Each point on the process is rated with regards to the effect of that point on importance to the customer. This allows for ratings that affect the quality of the final goods to be higher rated than say point that merely provide financial benefits.
The intention of the matrix is to rank the inputs vs the outputs in order to show the inputs that have the greatest impact on the outputs.
In larger projects this matrix would be utilised to reduce the amount of inputs to be assessed in a DOE or trials based on the weighted score.
Outputs:
Hole refers to both the presence of a hole and the non presence of a hole
Burr refers to presence of a burr or no presence of a burr.
Tool life refers to the tool life of the drill.
Each output is Rated for importance to the end user. For the example below the presence of a hole is the most important factor so rated with a 9, the tool life is rated as a 3 as it will only result in a cost of manufacture increase but essentially will not affect the end product to the customer.
The input variables cover causes highlighted in the Fishbone Diagram
The intention of the matrix is to rank the inputs vs the outputs in order to show the inputs that have the greatest impact on the outputs.
In larger projects this matrix would be utilised to reduce the amount of inputs to be assessed in a DOE or trials based on the weighted score.
 |
| C&E Matrix: Weighting |
Failure Mode Effect Analysis:
A failure mode effect analysis has been completed on the process to further aid the assessment the impact of failure modes on the Process based off the RPN Number for the process.
The excerpt from the FMEA below shows the headings that are assessed within an FMEA.
These are then assessed based on Severity, Occurance and Detection.
Col. 1 Input: eg Micro Drilling
Col. 2 Potential Failure mode: eg Drill Damage During Installation
Col. 3 Effect of the Failure mode: eg Incomplete or Complete Hole with Burr
Col, 4 Severity of this Effect. Severity of 8 is assigned both of these.
Col. 5 Potential cause. eg Drill tip damaged by hitting off the bar within the machine during setup of the tool length.
Col. 6 Potential of the occurance: 3
Col. 7 Current process controls: eg 100% Visual Inspection
Col. 8 Detection Rate: 1
Col. 9 RPN is the Risk Priority Number for the Failure mode.
Col. 10 Actions required: Eg trial on drill to see if this step could cause drill failure
Col. 11 Owner of Action.
Col. 12 Actions Taken
Col 13-16 RPN after actions completed.
 |
| FMEA Example |
The Severity, Occurrence and Detection rates are defined within standard tables that rate them based on the impact.
Severity assesses the impact of the Failure mode from 1 - 10 with 1 having no effect and 10 resulting in a failure mode that could happen without warning or endanger an operator. For our project example below a rating of 8 is assigned as it will disrupt the production line and part are scrapped if the defect is present.
Occurance is assessed vs failure rate or process Cpk. This rating can be difficult to define as it typically will be based on opinion vs facts. Where historical facts are available these should be utilised. A rating of 1 reflects an occurance of 1 in 1,500,000 and a rankingof 10 reflects a rate of 1 in 2., For this example a rate of 3 is specified as it is believe that the failure mode would be an isolated mode of failure but may happen if not addressed.
Detection is based on the ability of the process to detect the failure mode. 1 refers to a process where detection is almost certain. A rating of 10 reflect where detection is almost impossible, For this example a detection rate of 1 is selected as we have 100% inspection for this defect.
