CreateASoft, Inc.
The Process Improvement Company

Achieving and maintaining Lean and Six Sigma with Simulation.



Hosni Adra
Product Manager/Partner
 

Introduction
 

• About CreateASoft, Inc.
  -- In business since 1992
  -- Provides software, and simulation consulting services.
• Simcad Pro
  --  Process Modeling and Simulation tool that’s been successfully applied to multiple industries.
  
   

Overview

• Refresher on lean and Six Sigma.
• Using simulation to achieve a lean environment.
• Using simulation to achieve Six Sigma.
• The role of simulation in maintaining and fine tuning the attained goals.

What is Lean?

• Set of methods and concepts used to
  -- Reduce waste.
  -- Decrease WIP.
  -- Provide a streamline flow.
• Lean concepts are not industry specific.
  -- Can benefit both the service and manufacturing environment.

Key Stages of Lean application

Demand -> Flow -> Leveling -> Lean System

• Demand identified by
  -- Takt time, buffer inventory,safety inventory,…
• The Flow
  -- Continuous flow, work cells, Kanban system, FIFO lanes, …
• Leveling
  -- Paced withdrawal, Heijunka (load leveling)…

Goals of Lean systems

• Stabilize your processes.
  -- Review capabilities, labor, and material flow.
• Standardize processes and flow.
• Simplify, through Kaizan principals.
  

Key Lean concepts

• Takt time
  -- Available production time/total quantity desired.
• Cycle Time
  -- Time that elapses from the beginning of the operation until completion, also known as processing time.
• Value added time.
• Non value added time.
• Process efficiency
  -- Value Added Time / Total time.

Kanban System

• One of the most widely used terms in lean implementation.
• Implements a pull system.
  -- Only produce what’s needed downstream.
  -- Create production orders to upstream processes through signals or bins.
  
  
  
   

What is Six Sigma?

• System of management to achieve lasting business leadership and performance to benefit the business, its customers, shareholders, …
• A measure to define the capability of any process.
• A goal for improvement that reaches

Six Sigma and Quality

• Six Sigma represents the capability of a core business process as measured in defects per million opportunities.

DMAIC Overview
 

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Benefits of Lean and Six Sigma.

• Projects that are lean pay off in inventory and manufacturing cost reduction.
• Six Sigma projects working on improving quality (reduce defects) provide improved production rate and customer satisfaction.

The role of simulation

• Simulation provides a tool to analyze, visualize, and experiment.
• Improvement ideas are tested and analyzed before implementation.
• Migration scenarios can be tested.
• Forecasting and scheduling.
  
  

Where to start?

• Identify the Goal.
  -- Simulating without a defined goal does not generate results.
• Identify the processes involved in the environment.
• Define and collect metrics from existing line.

Simulation - First Step

• Start with a process map.
• Define the process flow.
• Assign scrap rates, product specific flows, resources, …
• Simulate and validate of the model.
  
  
  
  
  
   

Simulation – Step 2

• Convert flow to a value stream map.
• Identify the processes contributing to value added time.
  -- The remaining processes contribute waste to the overall flow.
• Identify the process efficiency rating.
  -- Process efficiency = VAT / total time.
  -- Identify the “worst performers” in the current flow.

A Value Stream Map

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Things to watch for:

• Queue wait time can be misleading.
  -- Main objective: Reduce WIP.
• Large production batches lead to large WIP values and a deviation from Lean principals.
  
  
   

Achieving Lean – Step 1

• From the VSM determine the processes contributing to 80% of the waste.
• Determine the non-value added time in the flow.
• Simplify – determine processes that can be split to avoid long processing times.
  
  
  
  
   

Achieving Lean – Step 2

• Can the Kanban system be used?
  -- A set of parts waiting to be assembled at a process (Large WIP Values) may indicate a problem at the assembly process, while the actual problem is at the feeding process.
• Determine the Kanban size:
  -- There should be enough work on every process to allow it to operate while the next bin is being produced.
  -- How? Kanban size can be determined based on the cycle time of the upstream processes.

Achieving Lean – Step 3

• Define the worst case scenario.
  -- Document the differences between runs (save the logs).
  -- Compare results to determine which scenario produces the best outcome.
• Based on the goal, determine how close you are to the projected takt time.
• Simulate multiple product mixes.
  
   

Achieving Lean – Step 4

• Define the worst case scenario.
  -- If more than one is possible, then run all possibilities.
• Define the best case scenario.
  -- A lean flow should operate flawlessly.
• Goal
  -- A combination of the process changes that provide a lean environment in 80% of the cases.
  -- Provide a solution for high demand scenarios.

Applying Six Sigma Changes

• Six Sigma changes may include
  -- Changes in the process flow.
  -- Changes in resource allocation.
  -- Changes in product mixes.
  -- Changes in the number of items in the flow.
• Use the simulation model to apply the changes.
  -- Is our lean solution still intact?
  
  
  
  
  
  

Quality effect on the line
 

• By reducing scrap, there is more demand on upstream processes to produce items.
  -- Potential problem: down stream processes may starve, or utilization may drop.
• Is a reduced utilization a problem?
  -- The goal is to produce products based on a preset customer demand (takt time).
  -- If takt time is achieved with a lower utilization, the process can be expanded in the future without impacting the operation.

Maintaining progress
 

• Current business models require constant monitoring of the operation.
• After desired improvements are achieved, the flow will lose efficiency through time if proper monitoring is not performed.
  -- A large percentage of companies that achieve lean and Six Sigma fail to maintain improvement through time.

Maintaining improvement with simulation

• Simulation models can play a major role in maintaining progress and help in constant improvement.
  -- Time was invested in building a model that resembles the production line.
  -- Constantly apply changes on the line to model and perform analysis before implementation.
• Always maintain an updated model.
   

The role of forecasting

• By preloading the model with existing WIP, and forecasted orders, …
• Schedules generated…
• Help the production line while maintaining model state.
• Proactive role … predict problems before they affect your line.
  
  
  
   

SimCAD Pro approach

• Support Value Stream Map and process map.
  -- Computation of VAT, Process Efficiency, takt time deviation, and many others.
• Forecasting and scheduling.
  -- Load existing WIP, forecasted orders, and generate the best production schedule.
• Ease of model creation.
  -- Quick solution turnaround.

CreateASoft, Inc.
The Process Improvement Company

Achieving and maintaining Lean and Six Sigma with simulation.