LEAN Basic Tools Concepts - Part 4

5S
Purpose - To create and maintain a clean, safe and high performing workplace. 5S:
•Enables anyone to distinguish between normal and abnormal conditions at a glance
•Is the foundation for continuous improvement, zero defects, cost reduction and a safe work area
•Is a systematic way to improve the workplace, processes and products through employee involvement

5S Definitions
Sort: Clearly distinguish between needed and unneeded items and eliminate the latter
Set in Order (also known as Simplify): Keep needed items in their correct place to allow for easy and immediate retrieval
Shine (also known as Sweep): Keep the work area swept and clean
Standardize: Standardize clean up (the first three S’s)
Sustain (also known as Self-Discipline): Make a habit of sustaining established procedures

REDUCE BATCH SIZE


Purpose: Create minimum safe batch sizes
•Batch sizes often set by management based on industrial engineering formulas or demand for a fixed time period
•Both typically result in lead times and inventory generally 30% to 80% larger than process requires

When to Use It: To create a lean system operating at peak efficiency with lowest cost

How to do it:
Step 1: Calculate the following formula
Min Batch Size = Sl/2(1-X-Pl) where: S = Setup Time
l = Demand Rate
X = Defect %
P = Processing Time per Unit
Assumption: All products have the same demand and process parameters


Step 2: Account for variation in demand
The Min Batch Size formula does not account for variation in demand, which is addressed in two ways:
•Manufacturing: Additional finished goods inventory must be built in accordance with the safety stock formula (see slide 25)
•Service Applications: Safety stock is not possible and customers must wait in queue to receive value added service time. Formula for queue time is:
Queue Time ~= (Service Time/# of cross-trained servers)/(n/n-1)
Where n = approximate % capacity at which servers are operating


4 STEP RAPID SETUP (FOR SERVICE PROCESSES)

Purpose - Reduce interruption to value-add work

When to use it - On any process step where there is a significant lag time (setup or change over time) between the completion of one task and full productivity on the next task or activity

How to do it -
Step 1: Differentiate between serial and parallel setup activities
•Serial events: Activities that cannot or should not be performed with other activities
Example: All activities by a bank teller while dealing with a customer (don’t want to make a customer wait)
•Parallel events are events that could be performed while another task is being done
Example: Downloading a software file, processing data

Step 2: Convert serial setup activities to parallel setup activities
•Goal: Offload setup activities to some other person, activity or process so they no longer disrupt value add work
•Use brainstorming, motivating and other group activities and select improvement ideas
•Use Impact/Effort (4 box matrix) to prioritize efforts
•Re-examine serial activities to determine if they really are truly serial

Step 3: Streamline remaining serial activities
•Simplify, reduce, eliminate movement. Example: Moving printers/copiers to eliminate walking
•Use electronic aids where possible. Example: Bar-coding vs. writing/typing, electronic notepads hooked into databases vs. handwritten notes
•Manage system/network needs. Example: Computers to sort disparate information

Step 4: Eliminate adjustments, standardize work
•Examine the “ramp up” time in serial setup work – any time that reduces output
•Ask what prevents the process from operating at full speed during these time periods
•Be creative in finding ways to address these issues
Example: If people need to look up information, have it available through linked databases or keyword searches

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