Problem Solving is the heart of an enterprise continued success in improving product design, processes and systems that enables all organizations operational and system functions for systematization of objective performance to achieve profit requirements.

The success of an organization in today’s rapidly changing demands and environment necessitates the development of knowledge capital to drive and meet the rising performance requirements at a increasing accelerating rate. Already the high level of information accumulation at all level of society is accelerating. This has resulted in a great knowledge gap disparity between information availability and the ability of today’s resource seeking enterprises to harvest potentially available solutions that already exist in science but not yet in technology, and in technology but not recognize.

TRIZ is a Russian made Inventive Problem Solving approach which in recent years has increasing emerged as a very powerful tool to make a significant contribution to close the many gaps between discovery, science, technology and applications. As a problem solving tool, TRIZ organizes the thinking processes to systematically, examine a problem (product design, process failure, system and organization dysfunctions) using a methodological approach to seek clever solutions that have been blocked by our own psychological inertia as well as the continued reliance on inadequate thinking process.

In the design world, the needs for time compression from idea conception in creative innovations and technological development must comply with today’s fast speed race to succeed. Organization that are able to achieve this will accumulate knowledge capital for technological development.

One of the most important Lean Workflow Measures is Workflow Factor. The Workflow Factor measures how Lean the work process is. By definition the best Lean Workflow Factor is 1 as given by the following ratio:

Workflow Factor = Total Process Workflow Time / Standard Process Time

The Total Process Workflow is normally a given Delivery Cycle Time from Start to Finish. That is, from the beginning of the first process to the end of the last process.

Normally, Workflow Factor is measured by:
Wf Factor = Total Workflow Cycle Time / Total Standard Process Cycle Time

For example:
Wf Factor = 12 Days X 24 hours / 120 hours = 2.4

In other words, for every standard hour of work, the actual workflow time taken is 2.4 hours.

Defining the hours for each day run is a necessary requirement for a proper understanding of the use of one day’s hours. One work day may be defined as:
8 hours;
12 hours; or
24 hours.

The time taken for each order completion in terms of days depends on the hours worked per day, the number of shifts and duration of each shift.

Batch Flow Workflow Factor:
For a given order size, a batch workflow will usually have a poorer Workflow Factor. This is because of Accumulated Cycle Time, Waiting Time, Delay Time, Logistics Time, QA Inspection and Approval Time, etc.

Continuous Flow-Workflow Factor:
For Continuous Flow in small quantity such as a basket size, container size, bundle size or even one-piece quantity, the Total Workflow Cycle Time for an average order size will be smaller. This is because of the overlapping cycle time of smaller quantity flow concurrently at the same time, resulting in a shorter Total Process Workflow Cycle Time.

One-Piece-Flow Workflow Factor:
Flow at one-piece at a time tends toward a Workflow Factor of 1, provided that the work process is short and well connected to subsequent processes with a balanced process cycle time. Achieving one-piece-flow does not necessarily attain a Workflow Factor of 1 if the production line is unusually long and the process cycle time is subject to occasional cycle time imbalance. Occasional Cycle Time Imbalance can result in a Line Loss of up to 30% capacity even in a one-piece-flow line.

The use of a Cell-Line of about 12 operators comprising not more than 12 different operations can provide better control to secure balanced production time for reduced loss due to waiting, imbalance, delay, transfer, handling, etc.

What then constitutes a Lean Workflow? As a guide, the following measures can be used to gauge how well your production line is doing with respect to lean implementation:

Workflow Factor
Above 1 and up to 1.5 = Good Lean Line
Above 1.5 and up to 2.5 = Standard Lean Line
Above 2.5 and up to 5.5 = Average Production Line
Above 5.5 and up to 10.5 = Fair Production Line
Above 10.5 = Bad Production Line

For more information on Workflow Factor and Line Design for One-Piece Flow,
contact the author, Mr. C. H. Wong (Email: chwong@aprc.com)

How To Configure Your Production Workflow To Achieve Lean Production

Takt Time and Pitch Time

One of the most fundamental principles of Lean is for material to be pulled and flow down the value stream at the Takt Time throughput rate. Takt Time is the amount of time for each piece to flow down the production line in order to be able to meet the delivery order requirement. Takt Time is calculated based on the delivery quantity to be made, say 10000 units in a typical month of 21 working days of 8 hours per day (excluding lunch and tea breaks).

So, in this case, Takt Time is about 60 seconds:

Takt Time = 21 days x 8 x 3600 seconds / 10000 units  =  60.48 seconds

This Takt Time is the basis for configuring all production flow processes to about 20% less to provide a Pitch Time of 48 seconds. This 20% is the contingency factor for downtime, yield losses, rework and occasional material shortage.

Therefore, in this case, Pitch Time = 48 seconds

Pitch Time is the engineered process time to complete one unit at the standard work performance.

Lean 1st Principle

From the above, it can be said that the Lean 1st Principle is to establish the Takt Time.

Lean 2nd Principle

The 2nd Principle of Lean is to configure all process cycle times on the production line to about 20% less than Takt Time. This is the Nett Pitch Time

Configuring The Workstation Layout

In the concept of Lean, one-piece-flow is emphasized. Therefore, production lines with many processes should have one workstation each to work on the one piece flow.

If for some reason, the Pitch Time of a Capacity Constraining Resource (CCR) is more than Takt Time, the following formula can be applied to calculate the number of CCR workstations required to balance production:

No. of CCR Work Stations Required To Balance Production = Gross Pitch Time / Takt Time

How Should Work Stations Be Redesigned To Distribute Workload

The traditional Line Balance approach is to vary the number of work stations for each process so that process time is the same for every process . Although time is balanced, space, however, is not balanced. In Lean, processes with longer process times are redesigned and broken down into sub-processes of equal process time to achieve balance in time and space (see diagram at the top).

Conclusion

In order to achieve Lean Production Line design, the 3rd Principle of Lean is stated as follows:

Lean 3rd Principle

The 3rd Principle of Lean states that only one piece flows through each separate process in Gross Pitch Time, matching that of the Takt Time.

Applying the 3 Principles as explained above would provide the understanding on how to configure production workflow to achieve Lean production.

Why Basic-MOST and MTM Applications Are Useful in Manufacturing Engineering, Warehousing, Supermarkets and Distribution Centres

 I have been teaching Basic-MOST system for more than 25 years as a Certified Instructor for H. B. Maynard (Accenture LLP, USA) and I have also taught MTM-1 and MTM-2 and certified many engineers all over Asia from various industries, especially manufacturing assembly type operations, semi-automated assembly line and fully automated manufacturing processing line operations.

In my capacity as a consultant, I have applied Basic-MOST to world-class hypermarkets, as well as warehouses and distribution centres for country-wide goods distribution and store operations. I have also developed Garment Sewing Data for the Garment Sewing industry to facilitate process cost estimation, sewing line balance, man-machine layout design and establishing of operational methods based on manual time to machine time ratio.

Over the past 25 years of my training and consultancy work, I have amassed a great amount of real expertise to apply MTM-1, MTM-2, Basic-MOST, Mini-MOST, and Maxi-MOST for establishing Cycle Time of work processes.

Special Application In Manufacturing Engineering

How useful are the cycle time work measurement data derived from MTM-1, MTM-2, MTM-UAS, Mini-MOST, Basic-MOST, Maxi-MOST?

First we have to explain that MTM System and the MOST System of work measurement are all equally powerful tools at the disposal of manufacturing engineering application.

In the MTM system, it is possible to evaluate the design of assembly parts with respect to:

Design:
a) Part Handling
b) Part Inspection
c) Part Orientation
d) Design for Assembly
e) Design of Tooling, Fixtures and Jigs

Manufacturing:
a) Cell Line Design
b) Fixture / Jig Design
c) Process Cycle Time for Balanced Workflow
d) Number of Work Stations Required
e) Number of Operators

Cycle Time and Capacity:
a) Target Quantity Per Hour
b) Number of Operators for Cell Line
c) Capacity Per Line
d) One Piece Flow Quantity and Cycle Time
e) Spread-Over Production for Several Models on the Same Work Station

Contribution and Profitability Analysis:
a) Labour Cycle Time and Cost
b) Contribution to Burden and Overhead Per Unit
c) Contribution Per Weight
d) Contribution Per Critical Process Cycle Time
e) Contribution Per Product Labour Hour

Standard Data Development
This is one area where the most fruitful result can be achieved for long term gain in the company. This is where special process application data are established for the standardized operational method for:

a) Garment Sewing Industry
b) Automatic Semiconductor Industry
c) Hypermarket Operation
d) Warehousing Operations
e) Storekeeping Operations

The above data are generally used together by integrating them with in-house software system to generate information on:
a) Capacity Analysis
b) Availability Vs Shipment
c) Profit Forecast
d) Process Manpower Deployment
e) Sales and Product Line Planning

Which Work Measurement Tool To Use?

This depends on selection criteria:

a) Average Process Cycle Time
b) Man-machine operation
c) Operational method repeatability
d) Size and weight of the part
e) Layout movement of two or more operators
f) Assembly tools
g) Bulk handling equipment

Short To Intermediate Cycle Time Duration
For short cycle time and small light part assembly work with repetitive operation, MTM is advantageous. MTM can also be used in long cycle time assembly, system box-build manufacturing. As cycle time becomes longer, there will be greater variability in operational method from cycle to cycle and in this case, Basic-MOST will be the more adaptable and practical work measurement system to use.

Long Cycle Time Processes
MTM system includes use of MTM-UAS (minus the complicated special data for fastening applications) which can be useful in the intermediate to long cycle time environment and especially in areas where operational methods are not repetitive. However, the MTM-UAS needs to be taught by an instructor well-versed in MTM-1 and MTM-2 and understand a lot about higher datablock development. Adaptation of the MTM-UAS data for automated application may have to be factored in in order to apply it correctly.
Maxi-MOST can be considered to be the industry’s best tool for measuring cycle time in:
a) Long cycle environment
b) Light to heavy work
c) High variation in operational methods
d) Workload involving heavy handling by one or more operators
e) Short to long process time with material handling

Conclusion

High Variability and Long Cycle

Among all the work measurment tools for special use in long cycle, high variability operation environments, Maxi-MOST stands out because the sequences are all operationally measureable in a very simple way which cannot be matched by other work measurement tools. The Maxi-MOST sequences include:
a) Part Placement
b) Tool Handling
c) Machine Operation
d) Part Fastening
e) Manual Crane
f) Heavy Lift Crane
g) Trucking Operations of all types

Low Variability and Intermediate Cycle

Similarly for short to intermediate cycle where there are some variability in operational methods, Basic-MOST offers super fast analysis based on:
a) General Move Sequence
b) Controlled Move Sequence
c) Tool Use Sequence – Single Use
d) Tool Use Sequence – Multiple Use
e) Hand Working in Place of Tool – Single Use or Multiple Use
f) Equipment Use Sequence (Customization is Required)

Almost 100% of all operational work methods can be tagged and measured by the above work sequences. Basic-MOST application is fast, accurate and method specific to the work under study. It is truly an ingenious way to measure work for many industrial applications, especially those who work in manufacturing engineering or as consultants to industry.

Definable Operational Methods and Less Operational Method Variability

The MTM System is ideal for Design for Assembly applications as well as for use in Standard Data block development.

MTM-1
– Design for Assembly evaluation

MTM-2
– Cycle Time Development and development of process datablock

MTM-2X
– Similar to MTM-2 with some variability in distance selection

MTM-UAS
– Simplified system to analyze distance variability and operational method where the cycle time is of intermediate duration of a few minutes to 30 minutes

For more information on MTM and MOST system of Work Measurement, please contact:

The Administrator
Asia Pacific Research Centre
35 Tannery Road #06-09 Ruby Industrial Complex
Singapore 347740
Website: www.aprc.com
Email: administrator@aprc.com