DMAIC Phase Five - Control

Day By Hour Output Tracking

I calculated hourly targets for the line based off the constraint station and communicated the target for the line to the operators as a team with the line Team Leader. I then calculated the possible output for each operator based on the work content contained within their own workstation. I did this because I often see operators who, after there has been an issue on the line which results in a build up of WIP (Work In Process) before their station, continue to build only the hourly target for the line even if there is more capacity within their own workstation. I posted the targets on the last station on the line and asked the operator who works on that station to record hourly output on the tracker. This is a very useful tool in providing timely feedback which is visual for all to see.


Day By Hour Output Tracking



Standard Work Review Check Sheet

I trained the Line Team Lead to complete a daily standard work review using a check sheet. This standard work review is critical to ensuring that standard sequencing, standard inventory, standard layout & standard techniques are maintained on each of the workstations on the Transform line. This is an excellent tool however it is time consuming to complete a review which may take up to one hour to complete. It is challenging for a team lead to complete this every day, possibly on more than one production line, so we are now proposing training the Training, Engineering & Quality support functions to complete this activity also in an effort to spread the workload & keep each of the functions engaged in the Standard Work program.

Standard Work Review Check Sheet

DMAIC Phase Four - Improve

Documentation Update

 I updated new drafts of the work instructions to a) move work content which had been rebalanced between workstations to the correct work instructions & b) to remove any ambiguity within the work-instructions for the purpose of ensuring that standard methods & techniques are documented. These drafts were processed through the change request process by the Manufacturing Engineer for the line, and approved by the Manufacturing Engineer (ME), Quality Engineer (QE), Manufacturing Training Coordinator & Team Lead.

Standard Work Guidelines

I crated Standard Work Guidelines for each of the workstations on the line documenting the Sequence, WIP levels to me maintained at the workstation, Layout of the workstation.
I processed these documents through the change request process for approval by the ME, QE, Manufacturing Training Coordinator & Team Lead.
Formal training will be documented for all of these updates & changes by the Manufacturing Training Coordinator.

Multiple Activity Charting

Multiple Activity Chart showing existing line design.

I drew up a multiple activity chart showing the first eight stations of the line all of which work in sub batches of five units. The examples shown both reflect the activities taking place during the 4th hour of the shift. I wanted to visually show how the different line designs impacted the flow of the process. I used this tool to show the operators how our newly designed line eliminated long batch set up times & was better balanced resulting in much reduced waiting times - shown below by the much reduced amount of area shaded in red with each cell representing 2.5 minutes.

Multiple Activity Chart showing proposed line design.

The salmon colour shows batch set-up times and the red shows the wait time required by an operator between receiving the next sub batch of five units. This tool was time consuming to put together but very effective in showing the improved design to the operators. Support staff were also impressed with the improvements themselves as well as how effective this tool is at showing the improvements to the line design.

DMAIC Phase Three - Analyse

Brainstorming

I completed a brainstorming session with the operators to gain their input as to the opportunities they could identify and to engage them in the project. I conducted the session on the manufacturing line to keep the operators within their daily work environment and therefore within their comfort zone. At the start of the session I explained that the purpose of the session was to identify waste on the line and/or opportunities to remove waste. The operators were slow to provide ideas at the beginning of the session however when I drew on some of the more confident members of the group, all of the others realised that they too had valuable input relating to the workstations they worked on and before long the task at hand turned from trying to draw out ideas, to managing the group so that all their ideas could get posted. After the session I drew up a list of the ideas and set up a meeting with the Line Team Leader, Manufacturing Engineer & Quality Engineer to review which of the ideas could be implemented within the time-line of the project, the ideas that may require a longer time-line to implement & the ideas that were not feasible to implement. I then met with the operators again to provide a feedback loop, informing them of the status & future plans for each of the ideas. The brainstorming session provided some excellent ideas as to what opportunities were open to us immediately and in the longer term and was critical to ensuring that the operators felt empowered within the project.

 

Takt Time.

I completed an analysis of Takt time to ascertain the frequency at which we needed to build one unit, in order to meet revised customer demand, this would tell us the required heart-beat of the line.

Existing Takt Time
Takt Time =	Net Available Time		450 min/day X 16 shifts + 200 min/day X 5 shifts		492000		547	Sec. Takt Time
	Customer Demand		900 units/month		900
Required Takt Time
Takt Time =	Net Available Time		450 min/day X 16 shifts + 200 min/day X 5 shifts		492000		364	Sec. Takt Time
	Customer Demand		1350 units/month		1350

Labour by workstation "Bar Graph".

In order to analyse the information I broke down the time needed for each operator to complete one unit through each process step and placed it onto a bar chart. This provides a visual representation of the work to be completed by each operator. I included a continuous black line to signify the takt time & a broken line to signify the takt time when the yield of the process is taken into account. If any of the bars rise above the broken line it means that that workstation contains too much work content to be able to meet the monthly build plan requirement. I also colour coded each bar with batch work orange, machine cycles green; load/unload machines black & manual work blue. In colour coding these activities I can see if an operator has a lot of batch work to complete at a start of a batch which will result in a "first boat effect" at the start of each batch. I can see if an operator is being constrained by a machine cycle time and whether or not they are working or idle during a machine cycle. I can easily see how well balanced the work is between each of the operators workstations. In an ideal world each bar would be identical in height, meaning that all operators had exactly the same amount of work content to complete. It is critical to be able to identify each of these situations in order to identify and therefore eliminate waste.

The main activities that I've completed in the analysis are:

1.      Excessive batch work at many stations - I propose to remove as much of this work as possible from individual workstations and have these activities completed by one operator.

2.      Balance the workload - some operators on the line complete as little as 33% of the work completed by their co-workers. As part of my analysis I have identified a much more level balance of work between each of the operators/workstations.

                         Before Analysis                                                                    After Analysis

Here we can see by the graph that the distance between the top of the bars and the black line above them is greatly reduced in the after analysis graph. This means that waiting time or "fresh air" as I call it has been reduced. We can also note from the graphs that there are 13 bars/operators in the before, the same work is divided between 12 bars/operators in the after graph resulting in a reduction in the headcount required to staff the line. We can also see that much of the batch work (orange) has been removed for individual work stations and given to an individual workstation who will complete much of the prep work required for individual workstations.

This task was relatively straight for as I had completed the time studies myself and as a result was knowledgeable on the process and how it could be moved and divided to re-balance the work content.

WIP Analysis using "Little's Law".

 I used Little's Law which is the mathematical relationship (Throughput time = Work In Process X Cycle Time) to look at controlling the amount of WIP at each work station.

Standard Work.

In order to implement Standard Work I used a software package called Timer Pro Professional to analyse the following;

1. Sequence; a) the sequence in which tasks are performed & b) the sequence in which units are processed through each step of the work-station.
2. Inventory; how many units are present at a workstation & what is the minimum inventory used to keep the line flowing.
3. Layout,; is the line layout & station layout optimised for efficient & safe work practises.
4. Time/Technique; are the techniques used by the operators standard and adequately documented in process work instructions so as to ensure the standard can be maintained and improved on. By reducing variation in techniques we reduce variation in the process time required to complete the task,

I camcorded a unit being processed through each workstation by multiple operators. In order to do this I had to set up the station with a vision system (see monitor below) as most workstations utilise a traditional micro-scope with two eyepieces, whereby only the operator can actually see the detail being performed. This set up allowed me to view the detail of each of the elements of the process step, before completing a comparison of techniques used by each operator & ensuring the technique is adequately documented in the associated work instruction. In order to reach agreement in standardising some of the techniques, Manufacturing & Quality Engineering functions needed to work with operators to decide which of the techniques used should be made the standard.

DMAIC Phase Two - Measure

In the measure phase I used Time Study to;

· Measure the work content for the entire process with a view to measuring how balanced the work load is between each of the stations/operators on-line.

This was a particularly delicate task as it involved not only observing, but timing people doing their work. Being observed makes most people uncomfortable mainly because it leaves them open to possible questions and/or criticism. I was very conscious that the incorrect environment could negatively affect the studies so in an effort to ensure that the operators were at ease with me observing them, I set up a kick off meeting the day before I was due to commence the studies to share with the operators what a typical study would involve, when I'd complete the studies, why I was completing the studies, what I needed from them & finally who would be studied. In relation to who would be studied I clarified that anybody who was fully trained on a process would be suitable to complete the study with, and I did not wish to complete studies with specific individuals, this I think removed any ideas the operators may have had that I was "going after" any one individual.

Completing the task itself consisted of noting each of the elements for a process step, and then measuring & recording the actual time it took to complete each of those elements - I completed this task for 10 of the units. The time studies varied from being very monotonous to needing 100% concentration to ensure that the time for any particular element wasn’t missed. I think that it’s a good tool for getting a picture of the times required to complete process steps. See example raw data below from one time study below.

I also completed a WIP Count to:

· Measure how much work in process (WIP) was on the manufacturing line, with a view to examining if any stations are seeing excessive build-up of WIP and if stations are repeatedly running out of WIP.

This task is pretty simple & involves counting & recording of how much WIP was on each of the workstations of the line at various times throughout the shift & repeating this task daily for a period of time. See example raw data below.

DMAIC Phase One - Define

Introduction

My name is Pat O'Shea, welcome to the Lean Six Sigma Transform Project Blog. The purpose of the blog is to share updates on my Lean manufacturing project which I'm completing on a manufacturing line in the medical device facility where I work. The goal of this project is to increase by 50% the output of this manual assembly line staffed by 13 operators utilising existing resources. I will follow the DMIAC process to implement the project.

Lean Six Sigma Definition

Lean Six Sigma is a synergized managerial concept of Lean and Six Sigma that results in the elimination of the seven kinds of wastes/muda (classified as Transportation, Inventory, Motion, Waiting, Overproduction, Over-Processing, and Defects, ) and provision of goods and service at a rate of 3.4 defects per million opportunities (DPMO) . A mnemonic for the wastes is "TIMWOOD".

More recently an 8th waste is sometimes added & listed as "underutilised human resources".
For more information on lean Six Sigma visit http://en.wikipedia.org/wiki/Lean_Six_Sigma

 

Lean Six Sigma Road Map



Define

In the define phase I used the process map tool in order to:

• Define the current processes.
• Build a step-by-step picture of the process for analysis, discussion & communication.
• Identify potential areas for improvement in a process.

I found that process mapping tool was very useful in gaining a basic understanding of the process that I am about to start working on. It also proved useful to ensure that all team members have at least this same basic level of understanding of the process & to my surprise a few team members learned something they didn't already know just by looking that this basic flow chart.

I also used the team charter tool to:

• Outline the scope, goals & deliverables of this lean improvment.
• As the project deveops it wil provide early indications of risks or barriers to the success of the project.

I found this tool very useful for providing an outline plan which the team can focus on executing.