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Day 5, Part 1 Basic Principles and Techniques of Productivity, Quality and Cycle Time Management. Software Project Planning and Management. Dr. Dennis J. Frailey Principal Fellow Raytheon Company. The Overall Planning Cycle. Manage Risks. Analyze Job. Generate Initial Plans. Generate

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day 5 part 1 basic principles and techniques of productivity quality and cycle time management
Day 5, Part 1Basic Principles and Techniquesof Productivity, Quality and Cycle Time Management

Software Project Planning and Management

Dr. Dennis J. Frailey

Principal Fellow

Raytheon Company

the overall planning cycle
The Overall Planning Cycle

Manage Risks

Analyze

Job

Generate

Initial Plans

Generate

Detailed Plans

Execute

Measure, Manage Productivity and Quality

outline
Outline
  • The basic principles of productivity
  • Customer value and value-added analysis
  • Principles of cycle time improvement
productivity is
Productivity is ...

The quality or state of being productive

Webster’s 9th New Collegiate Dictionary

Productive:

Having the power of producing;

Yielding or furnishing results, benefits, or profits

Webster’s 9th New Collegiate Dictionary

productivity is not being
Productivity is NOT being ...
  • Busy
  • Industrious
  • Virtuous
  • Wealthy
  • Hardworking
  • etc.

Productivity has to do with results (what and how much you produce), not with the means or methods of production or the characteristics of the producer

measuring productivity
Output

Productivity =

Input or Investment

Measuring Productivity
  • Productivity is usually measured in terms of how much you produce in relation to how much you invest
productivity measures
Productivity Measures
  • Products produced per labor hour
  • Return on investment
  • Bushels of grain per acre of land
  • Modules tested per week
  • Requirements validated per day

A farmer who invents a new method of growing that doubles the output per acre would be more productive than a farmer who works longer hours and doubles output per acre.

efficiency
Efficiency
  • Productivity is a measure of how efficient your process is
  • Thus the way you improve productivity is to make the process more efficient
  • Many principles of quality engineering and cycle time improvement are directly related to productivity improvement
work in process wip
Work in Process (WIP)
  • WIP or “work in process” is work in the midst of being done
    • code being tested
    • specifications being written
    • objects being designed
  • Excess WIP is work waiting to be done that is not being done -- waiting in queues instead
    • something is holding up the process
excess work in process is a key symptom
Excess “Work in Process” is aKey Symptom

Excess WIP is a symptom of low productivity, long cycle time, and process inefficiency

Another key symptom is non-value-added work. This will be addressed later.

excess wip usually implies a constraint or bottleneck
Excess WIP Usually Implies a Constraint or Bottleneck
  • When work is waiting to be done, it means that there is something holding it up
  • Usually this is some kind of limitation on resources or other form of process constraint
slide14
What Is a Constraint?
  • A constraint (bottleneck) is any resource with capacity less than the demand placed upon it
    • This could be a person, a computer, a network, a machine, etc.
  • The constraint regulates the output rate of the entire process
why is constraint management important
Why Is ConstraintManagement Important?
  • Improving a constraint provides capacity increase, often without capital investment
  • Management provides flexibility to respond to changes in customer demand
  • Reduces product cost as a result of increased output and improved efficiency

Hiking Boys Story

slide16
Where Are Your

Resources Focused?

If 100 people each worked to increase capacity by 1% on 100 different parts of the software development process, the 1 person working on the constraint would save the company thousands more than all the other 99 people combined!

slide17
Effective Utilization

Before deciding to take actions to improve the constraint, we must first understand the concept of effective utilization

slide18
TIME REQUIRED

R

EFFECTIVE UTILIZATION =

=

A

TIME AVAILABLE

Effective Utilization

Defined

REQUIRED (R)

AVAILABLE (A)

UNAVAILABLE

24 HOURS

Focus on decreasing ”R" and increasing “A”

I.e., decrease effective utilization!

slide19
Effective Utilization

-vs-

Productivity

  • Webster’s definitions:
    • Utilize: To make use of
    • Busy: Constantly active or in motion
    • Productive: Yielding or furnishing results, benefits or profits

We tend to measure utilization by how busy we are, BUT utilization tells us little about how productive we are.

why reduce effective utilization
Why Reduce EffectiveUtilization?

Running assets at a high effective utilization requires a costly cycle time trade off

WIP or CYCLE TIME

100%

EFFECTIVE UTILIZATION

per Erlang, 1917 (see Gross and Harris, pp 10-11, 101-102)

examples
Examples
  • Network performance vs load
  • Traffic flow vs load on freeway
  • Computer response vs load
  • Telephone dial tone delay vs load
  • etc.
slide22
Utilization

vs Productivity

  • High effective utilization will cause delays (cycle time) to increase greatly (increase investment) while output is increased only marginally, thus lowering productivity of the system
  • Lower utilization means the resource is available when needed most, thus reducing delays and raising productivity of the overall system
example firemen
Example - Firemen
  • Why are firemen usually sitting around the fire station, essentially idle?
  • Because they are needed ASAP when there is a fire.
slide24
Effective Utilization

And the Constraint

  • Reducing effective utilization is especially critical at the constraint, because it determines the performance of the system as a whole
  • To minimize effective utilization, we must make our assets more productive
    • This does not necessarily mean that they are busier!
ways to improve efficiency at the constraint
Ways to Improve Efficiencyat the Constraint
  • Repair analysis improves our ability to repair and maintain the constraint, so we can improve its availability (increase “A”)

Repairman

Story

more ways to improve efficiency at the constraint
More Ways to Improve Efficiencyat the Constraint
  • Flow balancing allows us to effectively increase tool availability (increase “A”)
    • Flow variability to the constraint increases the probability of the constraint running dry
    • Flow management helps control variability
  • Statistical process control techniques can decrease required processing time as well as increase tool availability (decrease “R”, increase “A”)
what constitutes customer value
What Constitutes Customer Value?
  • Customer value is the real target of any competitive business
  • The exact definition depends on the customer and the market
    • Sizzle vs steak
    • Features vs ease of use
    • Cost of operation vs comfort and safety
defining value
Defining Value
  • Correctly defining value is the first step of customer satisfaction
  • Cut out the tasks or features that do not directly or indirectly contribute to value
    • They add cost but do not provide appropriate benefit
dimensions of customer value
Dimensions of Customer Value
  • Low Costs / High Productivity
    • Product development/manufacturing efficiency
    • Attractive price
  • High Quality
    • Customer satisfaction
    • Reliability & few defects
  • Short Cycle Time
    • Rapid product development
    • Response to orders
the goal
Customer

Value

Productivity

Cycle Time

Quality

The Goal
  • Improve all components of the customer value triangle
without process change
Without Process Change ...
  • You can improve any one at the expense of the others

High

Quality and

Low Cost, but Slow

Fast,

Cheap,

but

Shoddy

High Quality,

but Slow and Costly

by changing process culture
By Changing Process & Culture ...

… you can improve all together

Satisfactory

Value

Good

Value

Better

Value

Even

Better

Value

weinberg s definition of quality
Weinberg’s Definition of Quality

“Quality is value to someone”

  • In Weinberg’s sense, value is quality
  • And the cost to produce value is the cost of quality
  • But the term “cost of quality” is usually used in a different context, to describe tasks we execute that improve quality
  • Keep this in mind as we continue in this course
who produces value
Who Produces Value?
  • Value is the result of the best software engineers doing their best work.
  • So software engineers produce value - and quality!
what are the costs of software development
WHAT ARE THE COSTS OF SOFTWARE DEVELOPMENT?

Total Costs

Value-Added

Non-Value-Added

Essential

Non Essential

value added costs
Value-Added Costs

Costs for tasks performed ...

  • Materials (e.g.., paper, software)
  • Labor hours (salaries)
  • Capital equipment (workstations, facilities)

… that produce value

  • Products
  • Customer satisfaction
  • Future labor that will not be expended
    • e.g.., reduced maintenance and repair
the strict definition of value added
The Strict Definition of“Value-Added”
  • Any activity that is part of the process is considered a value-added activity if it meets three criteria:
  • 1) Must change the product in some way
  • 2) Must make the product more desirable to the customer (i.e., the customer wants the change)
  • 3) Must be done right the first time
the strict definition
The Strict Definition
  • This very strict definition helps us open our minds
  • So we identify the proper targets for process improvement.
  • Anything that is not value-added is a suitable target for removal or improvement.
things not part of value added
Things Not Part of Value-Added
  • Features the engineer thinks are nice but the customer doesn’t care about
  • Moving a product around
  • Translating between incompatible tools
  • Repairing mistakes
  • Tests and inspections
  • Most management activities
  • Activities unrelated to the process
  • Many other things we tend to think of as “necessary” or “desirable”
    • And some of them are necessary!
some non value added activities
Some Non-Value-Added Activities
  • Management
  • Quality Assurance
  • Testing
  • ...

The term “value-added” is used to help us improve our processes. It is not meant to imply that the above tasks are not valuable or that the people who do them are dispensable.

non value added essential
Non-Value-Added Essential
  • Costs for tasks performed because the process is not perfectly efficient
    • Peer reviews
    • Evaluations, inspections, verification and validation
    • Metrics collection, storage and analysis
    • Extra reviews and verifications required by customer or company policy (usually because of past problems)
    • Certain overhead costs (benefits, support activities)
why are they essential
Why are they Essential?
  • They would not be necessary in a perfect world
  • But they are necessary with our current methods of product development and our current level of product development knowledge

Every process has some essential, non-value-added elements

another perspective
Another Perspective
  • Non-value-added but essential tasks are things we might wish we did not have to do
  • But if we did not do them, things would be worse.
  • However, we still can study them to find out how to minimize them, optimize them, and improve them
non value added not essential
Non-Value-Added, Not Essential
  • Tasks that are not value-added and that are not essential
  • Typically, these are tasks that we perform because we have not really optimized our processes
    • For example, things we have always done but no longer need to do
    • Or methods that once made sense but don’t any more due to newer technologies or changes in the organization or environment
examples of non value added not essential tasks
Examples of Non-Value-Added, Not Essential Tasks
  • Excessive paperwork or approvals
  • Waits for test equipment or “signoff”
  • Debugging due to sloppy design or coding
  • Costs resulting from bugs in our software development tools
  • Costs for activities unrelated to the process

These tasks should be eliminated or streamlined first, as they add cost for no useful purpose

some costs are especially painful
Some Costs are Especially Painful
  • High costs incurred later because of tasks not performed during software development (or not performed at the right time or in the right way)
    • Debugging
    • Correcting defects
    • Maintenance and repair
  • These can subtract value:
    • Loss of customer good will
    • Future labor that must be expended
typical value added categories
Typical Value-Added Categories

Value-Added

Non-Value-Added (costs $, no value to customer)

1) Customer Wants

2) Changes Product

3) Done Right the First Time

Essential

Non-Essential

  • Set-Up
  • Training
  • Planning
  • Customer-required test
  • Moving Data Between Steps
  • Many Quality Improvement activities
  • Extra paperwork
  • Waits
  • Delays
  • Bottlenecks
  • Counting
  • Installing Software Tools
  • Extra Un-wanted Features
  • Rework
  • Service
  • Modification
  • Expediting
  • Recall
  • Correction
  • Retest
  • Error Analysis
  • Design
  • Development
  • Fabrication
  • Documentation
  • Assembly
  • Process
  • Creation
  • Upgrade
  • Shipping
analyzing value added by task or category
Value-Added

Non-Essential

Essential

Non-Value-Added

Analyzing Value-Added by Task or Category

This is the first step of value-added analysis

  • List all of the tasks or task categories in your process
  • Then place each task into one or more of the three value-added classes
  • If a task fits more than one class, you may want to break it up into parts
example result of analysis by task category
Example Result of Analysis by Task / Category

Value-Added

Non-Value-Added (costs $, no value to customer)

1) Customer Wants

2) Changes Product

3) Done Right the First Time

Essential

Non-Essential

  • Estimating
  • Training
  • Planning
  • Customer-required acceptance test
  • Configuration Control
  • Inspections
  • Approval by 7 people!
  • Delays for test systems
  • Data conversion between design tool and coding tool
  • Wait for subcontracted hardware
  • Debugging
  • Service calls
  • Warranty costs
  • Fedex costs for patches
  • Loss of customer goodwill
  • etc.
  • Requirements analysis
  • Design
  • Coding
  • Documentation
  • Integration
  • Manufacturing
  • Packaging
  • Shipping
analyzing value added costs
Analyzing Value-Added Costs
  • This is the second step of value-added analysis
  • Each task can be assessed with respect to how much of its cost adds value
  • Often, a task will contribute some value but have some non-value-added elements as well
what are the units
What Are the Units?
  • The unit we measure for “cost”can be anything that is available …
    • Dollars
    • Labor hours
    • Percent of time spent
  • For initial analysis, the data do not have to be very accurate
    • Estimated percent of time spent
    • Estimated hours spent
suggested approach to apply these concepts in practice
Suggested Approach to Apply These Concepts in Practice
  • Take a typical process from your work environment and do a value-added analysis by task or category
  • For tasks that have some value-added and some non-value-added, estimate percentages of each
  • Estimate what percent of the overall process is non-value-added
  • Discuss how you might measure the costs (what units to use) using available information or information readily obtained
typical result
Typical Result
  • Value-added -- 35% of total cost
  • NVA Essential -- 20% of total cost
  • NVA Non-essential -- 45% of total cost
    • Top three items:
      • Rework due to design and coding errors -- 14%
      • Extra customer support -- 12%
      • Labor for individuals waiting for test equipment that is not available -- 11%
a dilemma in analyzing non value added costs
A Dilemma in Analyzing Non-Value-Added Costs
  • Sometimes we must introduce non-value-added tasks to reduce the costs and impact of other non-value-added tasks
  • This is a fundamental dilemma and a fundamental reason why we need to do more than analyze value-added
  • We discussed this a little when we talked about cost of quality analysis
analyzing the net cost of a process
Analyzing the Net Cost of a Process
  • ) Identify and list all steps or tasks of the process
    • Document each -- purpose, description, procedures, etc.
    • Include everything you do.
      • Best if you watch and record actual behavior of practitioners.
analyzing the net cost of a process1
Analyzing the Net Cost of a Process
  • ) For each task, do a basic value- added analysis:
    • Divide all tasks into Value-Added and Non-Value-Added
    • A task is “value-added” if it meets three criteria:
      • Changes the product
      • The change is wanted by the customer
      • It is done right the first time (is not rework)
analyzing the net cost of a process2
Analyzing the Net Cost of a Process
  • ) Divideinto Five Categories:
    • Costs of performing the task (value added)
    • Prevention costs (non value added, cost of quality)
    • Appraisal or evaluation costs (non value added, cost of quality)
    • Failure response costs (non value added, cost of quality)
    • Everything else - (unrelated costs, non-value added, non cost of quality)
categorizing tasks and subtasks
Non Cost of Quality

Cost of Quality (all non-value-added)

Non-

Value

Added

Cost of Non Conformance

Cost of Conformance

Value

Added

Prevention

Appraisal

Failure

  • Design
  • Development
  • Fabrication
  • Documentation
  • Assembly
  • Process
  • Creation
  • Upgrade
  • Shipping
  • Over-
  • head
  • Errors
  • Ineff-
  • icien-
  • cies
  • Training
  • Planning
  • Simulation
  • Modeling
  • Consulting
  • Qualifying
  • Certifying
  • Inspection
  • Testing
  • Audits
  • Monitoring
  • Measure-
  • ment
  • Verification
  • Analysis
  • Rework
  • Service
  • Modification
  • Expediting
  • Recall
  • Correction
  • Retest
  • Error Analysis
Categorizing Tasks and Subtasks
analyzing the net cost of a process3
Analyzing the Net Cost of a Process

4) Determine Costs

  • Determine the cost in labor or other units for each task
  • Sum for all tasks
example cost of a process
Non Cost of Quality

Cost of Quality

Cost of Conformance

Cost of Non Conformance

Non-Value Added

Value Added

TOTAL

600

100

450

95

300

450

400

275

200

150

150

3170

100%

Prevention

Appraisal

Failure

Program Design

Design Reviews

Code

Code Reviews

Unit Test

Integration Test

System Test

Configuration Mgt

Problem Solving

Rework

Retest

540

400

940

30%

60

50

110

3.5%

60

60

120

4%

40

35

300

450

400

275

1500

45%

200

150

150

500

15%

Example - Cost of a Process
what if you don t know
What if You Don’t Know?
  • Often at this point you have tasks you do not know how to handle:
    • Don’t know the cost
    • Don’t know if value-added
    • Don’t know the true impact of the task
  • Which leads us to step 5 - Defining a metrics program to help with this analysis
analyzing the net cost of a process4
Analyzing the Net Cost of a Process

5) For each task, determine:

  • Customer requirements (input & output)
  • Supplier requirements (input & output)
  • Measures that determine if requirements are met
  • Measures that determine why or why not
  • Measures that determine the cost of the task
analyzing the net cost of a process5
Analyzing the Net Cost of a Process
  • ) For each task:
    • Analyze the measurement requirements
      • Is it measured now?
      • Can it be measured?
      • Should it be measured?
    • Determine the level of effort or cost to measure
you will use the measures to determine
You Will Use the Measures to Determine ...
  • What tasks cost the most
  • What tasks are worth improving
  • What tasks should be eliminated
analyzing the net cost of a process6
Analyzing the Net Cost of a Process
  • ) Look for opportunities to improve
    • Tasks that are not value-added but have high cost
    • Costs of non-conformance
comments
Comments
  • The more mature the process, the more tasks in the prevention column and the fewer in the appraisal and failure columns
  • Your process maturity may have a lot to do with what techniques work and what techniques do not work
effects of maturity on costs
60

50

40

30

20

10

5

2

3

4

1

Effects of Maturity on Costs

Total COQ

External

Failures

Cost as a Percent of Development Cost

Internal

Failures

Appraisal

Prevention

SEI Maturity Level

As reported by Knox (see references)

comments continued
Comments (continued)
  • By tracking these costs and looking at the impact of process changes, you can determine the cost and the benefit of changes
  • Thus you can optimize the process
more comments
More Comments
  • If you track current costs
    • You open your eyes to the cost of non conformance
  • If you track the effect of changes
    • You learn what works to improve your process
note that efficiency improves three perspectives
Customer

Value

Low Cost or

High Productivity

Short Cycle Time or Schedule

Quality (Fewer Defects; Customer satisfaction)

Note that Efficiency Improves Three Perspectives
summary
Summary
  • Understanding value is the starting point for effective and efficient processes
  • Value-added analysis can help identify the best places to focus improvement efforts
  • Just because something is “non-value-added” does not mean it is not worthwhile or necessary or good
references
References
  • Knox, 1993, Raytheon studies reported by Houston and Keats, Software Quality Matters, vol 5, no 1 (Spring, 1997), U. of Texas SW Quality Institute
  • Musa, John D, 1992, “The Operational Profile,” in Software Reliability Engineering: An overview.
  • Weinberg, Gerald M., 1992, Quality Software Management, Volume 1, Systems Thinking, Dorset House, New York, ISBN 0-932633-22-6.
outline1
Outline
  • Why Cycle Time is Important
  • Symptoms and Causes of Cycle Time Problems
cycle time reduction
Customer

Value

Short Cycle Time or Schedule

Low Cost or

High Productivity

Quality (Fewer Defects; Customer satisfaction)

Cycle Time Reduction

Time costs money

Cutting cycle time saves money and can increase quality

The issue: how to do it effectively

why cycle time is important
I Need

that Software

no later than next week! Why is it taking so long?

We’ll work overtime to get it out, sir.

But we’re already working overtime!

Why Cycle Time is Important

Yes, Sir!

Right Away,

Sir.

importance of low development cost for new product development
ON TIME, CORRECT PRODUCT COST, BUT

WITH 50% DEVELOPMENT COST OVERRUN

0

5

10

15

20

25

30

35

% LOSS OF TOTAL PROFIT

Importance of Low Development Cost for New Product Development

Mckinsey & Co. Analysis of new product introduction profit and loss

importance of product cost for new product development
ON TIME, CORRECT PRODUCT COST, BUT

WITH 50% DEVELOPMENT COST OVERRUN

ON TIME AND BUDGET, BUT

PRODUCT COST 9% TOO HIGH

0

5

10

15

20

25

30

35

% LOSS OF TOTAL PROFIT

Importance of Product Cost for New Product Development
importance of cycle time for new product development
ON TIME, CORRECT PRODUCT COST, BUT

WITH 50% DEVELOPMENT COST OVERRUN

ON TIME AND BUDGET, BUT

PRODUCT COST 9% TOO HIGH

ON BUDGET, BUT PRODUCT IS SHIPPED 6 MONTHS LATE

0

5

10

15

20

25

30

35

% LOSS OF TOTAL PROFIT

Importance of Cycle Time for New Product Development
why improve software development cycle time
Why Improve Software Development Cycle Time?

To improve the organization’s capability to develop software products quickly.

This does not necessarily mean that you will always need to develop products quickly

  • Not all situations require short cycle time
  • But for those that do, you are more competitive
what if you don t need short cycle time
What If You Don’t NeedShort Cycle Time?
  • You can use this capability to:
    • Achieve competitive costs
    • Start software development later in the program cycle
    • Allow less time to change requirements
    • Get software development off of the critical path
a common cycle time issue
A Common Cycle Time Issue

It took so long to develop the software that the customer’s needs changed. This resulted in excessive rework, higher costs, and further delays

We’ve changed this requirement.

The key is to develop the software quickly so today’s needs can be met

how can cycle time be improved
How Can Cycle TimeBe Improved?
  • The following video illustrates how to improve cycle time in an area that many of us are familiar with - building a house
  • As you watch, think of ideas that might be applicable to software development
some lessons from the cycle time video
Some Lessons from the Cycle Time Video
  • What did they do?
  • Is there a software counterpart?

Things they did:

+_%$#@&

~~~~~~~~~~

~~~~~~~~~~~

~~~~~~~~~~~

how is cycle time improved
How Is Cycle Time Improved?
  • Doing every process step faster?
  • Working longer hours?
  • Piling up work?

Faster!!!

how is cycle time improved1
How Is Cycle Time Improved?
  • Doing every process step faster?
  • Working longer hours?
  • Piling up work?

Faster!!!

cycle time improvement is
Cycle Time Improvement Is ...

Improving the Process

cycle time improvement is1
Cycle Time Improvement Is ...

Improving the Process

Reducing the Critical Path

cycle time improvement is2
Cycle Time Improvement Is ...

Improving the Process

Reducing the Critical Path

Eliminating Waits, Queues, Bottlenecks

cycle time improvement is3
Cycle Time Improvement Is ...

Improving the Process

Reducing the Critical Path

Eliminating Waits, Queues, Bottlenecks

Helping People work Smarter

cycle time improvement is4
Cycle Time Improvement Is ...

Improving the Process

Reducing the Critical Path

Eliminating Waits, Queues, Bottlenecks

Helping People work Smarter

Increased Cycles of Learning

cycle time improvement is5
Cycle Time Improvement Is ...

Improving the Process

Reducing the Critical Path

Eliminating Waits, Queues, Bottlenecks

Helping People work Smarter

Increased Cycles of Learning

Reengineering the Process

symptoms of cycle time problems
Symptoms ofCycle Time Problems
  • Long waits and queues
  • Lots of “work in process”
  • High inventory levels
  • Excessive overtime

Tickets -->

How long is

this line?

major contributors to slow cycle time
Major Contributors toSlow Cycle Time
  • Bottlenecks and constraints
  • Barriers
  • Inefficient processes
  • Inadequate training
  • Variability
bottlenecks and constraints
Bottlenecks and Constraints

Places in the process that inhibit efficient flow of work

  • Symptom: excess WIP or “work in process”
    • work waiting to be done that is not being done -- waiting in queues instead
    • something is holding up the process
  • Causes: limited capacity, poor processes, poor execution, or various barriers imposed by the organization
example process
Example Process

Deliver

Take Order

Where could the bottlenecks be?

Box

Toppings

Slicer

Pizza Oven

Crust

barriers
Barriers

Things that prevent you from going faster, such as budgetary limits, head count limits, lack of people or equipment, process problems, missing data, regulations, etc.

sample barriers
Sample Barriers
  • Approval processes
  • Excessive paperwork
  • Limited space
  • Limited budgets
  • Wasteful processes
  • Defective information or material
  • …..
dealing with barriers
Dealing with Barriers
  • Question why barriers are there
    • Often they are the remnants of past problems and no longer need to be there
      • Obsolete approval procedures
      • Redundant checks and balances
    • Sometimes the barriers have benefits but the organization does not understand their consequences
      • The “cure” may be more expensive than the problem
organizations often resist removal of barriers
Organizations Often ResistRemoval of Barriers
  • There are many reasons, such as …
    • Political factors
    • Power issues
    • How performance and success are defined
    • Fear of change

Exercise

What barriers does your organization resist removing and why?

lack of training contributes to slow cycle time
Lack of Training Contributesto Slow Cycle Time
  • Inadequate Training - people do not know what to do, or how to do it most effectively
    • So it takes them longer to do the work
  • Investment in training usually pays off well
  • --
    • But it requires foresight and faith
process contributes to slow cycle time
Process Contributesto Slow Cycle Time
  • Inefficient Processes - processes containing steps that do NOT ADD VALUE
    • All processes have inefficiencies
    • Most processes can be improved in efficiency
  • Variability - in processes, materials, skills, etc.
    • Variability is natural
    • But it can be controlled
special notice
Special Notice
  • For the next exercise, each student should bring a pair of dice
    • Actually, one die per student will do
  • And five coins or other tokens
  • And have some desk space free
references1
References
  • Deming, W. Edwards, Out of the Crisis, MIT Press, 1982.
  • Goldratt, Eliyahu M. & Jeff Cox, The Goal, (North River Press, 1984.) Also, Theory of Constraints, It’s Not Luck, and Critical Chain Management.
  • Swartz, James B., The Hunters and the Hunted, (Portland, Oregon, Productivity Press, 1994) ISBN 1-56327-043-9.
outline2
Outline
  • Variability Experiment
  • Definitions, Terms and Concepts
  • Solutions to Cycle Time Problems
    • Reducing Variability
    • Reducing Work in Process
  • Observations and Caveats
variability experiment1
Variability Experiment
  • Line up 5 tokens, like a train
  • Each turn, move tokens right
    • See rules on a later slide
  • How many turns does it take to move the leftmost token 15 positions?

Rules:

    • Round 1 will have low variability
    • Round 2 will have high variability
    • Round 3 will have high variability but higher capacity
token setup for experiment
Token Setup for Experiment

 o o o o ... Round 1

 o o o o … Round 2

 o o o o … Round 3

^ ^ ^

Left Token Right Token Positions to Move to

You may execute the rounds sequentially or in parallel.

round 1 rules
Round 1 Rules
  • Each turn, move each token 3 places, starting with the one on the right (3 places right, per turn)
  • Result of first turn:

o o o  o o o …

  • Result of second turn:

o o o o o o  ...

How many turns does it take for the leftmost token to move 15 places to the right?

round 2 rules
Round 2 Rules
  • Each turn, move each token n places, starting with the one on the right, where n is a number from 1 to 5 determined randomly by rolling a die -6’s don’t count.
    • Roll the die separately for each token
    • A token cannot move past another
  • Note that the average move is 3 places
  • Possible result from first turn

o o o o  o o …

round 3 rules
Round 3 Rules
  • Each turn, move each token n places, starting with the one on the right, where n is a number from 1 to 6 determined randomly by rolling a die -6’s do count.
    • Roll the die separately for each token
    • A token cannot move past another
  • Note that the average move is 3 1/2
  • Possible result from first turn

o o o o o  o …

why variability results in longer cycle time
Why Variability Results in Longer Cycle Time
  • Slower tokens block faster ones
  • If you have a low roll on the die you cannot take advantage of opportunities to “catch up”
  • Even with higher average capacity (round 3), variability results in slower cycle time
definitions terms and concepts

Definitions, Terms andConcepts

The next few slides address some basic cycle time terminology

cycle time is
Cycle Time is ...

The time required to execute all activities in a process

  • This could be:
    • First operation to ship
    • A single operation
    • A group of operations
    • Customer order to product delivery
  • Cycle time includes actual processing time …… and all waiting time
    • Consider a “10 minute” oil change
lead time is
Lead Time is ...

The maximum time the customer will wait between order placement and product delivery.

  • What is:
    • Your customer’s lead time?
    • Your potential customer’s lead time?

How long

will it

take?

Here’s

my

order!

cycle time vs lead time
Cycle Time vs Lead Time
  • To be competitive, you must make:

Cycle Time < Lead Time

  • Otherwise, you lose business
  • Or else orders have to be started on speculation, which means higher risk of rework or failing to satisfy the customer
throughput is
Throughput is ...

The number of products produced per unit of time

  • This could be:
    • Modules tested per day
    • Components produced per week
    • Defects corrected per month
    • etc.
  • Throughput is a measure of the output of a process
how to measure cycle time
CT1 + CT2 + CT3 + CT4 +...+ CTn

Cycle Time =

n

How to Measure Cycle Time?

Static Cycle Time

The average of the actual cycle times (CT) experienced by some number (n) of products

using this measure
Using This Measure
  • This can be used to measure cycle time for many situations
    • For example, measure the cycle times of the tokens in the variability experiment
    • Or measure the cycle times for cars being serviced in a “10 minute oil change” station
  • But this is not always easy to measure when many of the products are only partway through the process
    • So we need a dynamic measure
a measure to use when static cycle time is not convenient
Cycle Time =

WIP (products being developed)

THROUGHPUT

A Measure to Use when Static Cycle Time is Not Convenient

Dynamic Cycle Time

The total work in process (WIP) divided by the throughput of the process

This equation can be shown from queueing theory. See Gross and Harris, in reference list, p83.

revised variability experiment
Revised Variability Experiment
  • Take 5 turns for each round
  • Measure the total number of tokens that reach the 15th position
  • After 5 turns, measure WIP
  • Also measure throughput, cycle time, etc (see next slide)

Think of this as a 15 step process, with the tokens being work going through the process

what makes cycle time high
What Makes Cycle Time High?
  • Inventory or work in process (WIP)
  • Higher overhead, longer delays
  • Process flow variability
  • Excessive waiting and long queues
  • Complexity of processes
  • Redundant and unnecessary steps

These are all related to each other

3 steps to cycle time improvement
3 Steps to Cycle Time Improvement
  • Reduce variability
  • Simplify the process
  • Reduce WIP

This order is recommended

Due to time limitations, we will only address the first and third of these in this module.

Process simplification will be addressed in the next module

variability increases cycle time
1

2

3

4

LSL

USL

LSL

USL

LSL

USL

LSL

USL

Variability Increases Cycle Time

OUTPUT FROM FOUR DIFFERENT

PROGRAMMING SHOPS

If price and delivery were equal, which supplier would you buy a product from?

sources of variability
Sources of Variability
  • Movement of programs or documents between workstations or systems
  • Machines or software not being available
  • Hot lots / priority tasks that disrupt normal activity
  • Software defects that require rework and debugging
  • Special cases that require holds and delays
  • Inconsistent processes and procedures
  • Excessive approval requirements
  • Hundreds more...
slide135
Expediting via Priority Tasks
  • The tendency is to establish many levels of priorities
    • Hot
    • Super hot
    • Immediate
    • Per the boss
  • Pressure exists to raise the number of priority tasks
  • The list always grows
other problems resulting from priority tasks
Other Problems Resulting from Priority Tasks
  • Managing priorities consumes many resources
  • And it delays other jobs
slide137
Cycle Time Multiplier for Non-Expedited Jobs

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

Percent expedited

Expediting vs Cycle Time

  • When we expedite a product, other products are delayed
  • In some cases, each product waits until it is expedited before it moves at all
slide138
EXPEDITED

LOTS

DELINQUENT

LOTS

NUMBER

OF

SHIPMENTS

7 14 21 28

CYCLE TIME (DAYS)

Variability Management Must

Minimize Expediting

BAU

With managed priorities, you improve the normal case and reduce the need for “priority jobs”

NUMBER

OF

SHIPMENTS

7 14 21 28

CYCLE TIME (DAYS)

a strategy for managing priorities
A Strategy for Managing Priorities
  • Allow only two priorities
    • Hot
    • Not hot
  • Control the maximum percentage of “hot” (less than 8% to 10%)
    • If you add a hot job, you must subtract another
    • This requires discipline (and faith that it works!)
further management of priorities
Further Management of Priorities
  • Monitor distribution throughout the process
    • Do not plug up one operation or individual with priority tasks
  • Monitor frequently
  • Remove tasks from the priority list when they don’t really need priority
slide141
Cycle Time, Utilization

and Variability

WIP or CYCLE TIME

100%

EFFECTIVE UTILIZATION

slide142
WIP or CYCLE TIME

SOME VARIABILITY

100%

EFFECTIVE UTILIZATION

Higher Utilization Increases

Cycle Time

slide143
Variability Affects the

Extent of the Added Delay

WIP or CYCLE TIME

SOME VARIABILITY

NO VARIABILITY

100%

EFFECTIVE UTILIZATION

slide144
Variability Reduction

Opportunities

Variability

Low

High

WIP or CYCLE TIME

Output

Opportunity

Cycle Time

Opportunity

EFFECTIVE UTILIZATION OR THROUGHPUT

slide146
WIP

Dynamic Cycle Time =

THROUGHPUT

High WIP = High Cycle Time

  • Any intermediate work in the system is WIP.
  • Anything that is not being actively processed is excessive WIP.

For related background, see Gross and Harris, in reference list, p83.

slide147
Examples of Excessive WIP for Software
  • Code waiting to be tested
  • Designs waiting to be coded
  • Specifications waiting to be inspected
  • Change requests waiting for approval
  • Hundreds more...
smooth flow ideal process
Smooth Flow - Ideal Process
  • The ideal process flows smoothly, like a train running on tracks.

Note: tracks are empty most of the time

uneven flow typical process
Uneven Flow - Typical Process
  • The typical process runs unevenly, like vehicles on a city street
  • Lots of exits and entrances
  • Vehicles of varying sizes and speeds
  • Some drivers uncertain of what they want to do
  • Lots of stoplights to “control” the flow (mainly to prevent collisions)

Note: streets are usually crowded - with WIP!

techniques for obtaining smoother flow
Techniques for ObtainingSmoother Flow
  • Identify bottlenecks and constraints -- and manage/optimize them
  • Utilize pull systems instead of push systems
  • “Conduct the orchestra” (keep everyone going at the same speed)
  • Flow management systems
  • .....
too much measurement
Too Much Measurement!
  • The tendency is to measure too much and in too much detail
    • Rough estimates usually identify the biggest problems and opportunities
some of the problems solutions are technical
Some of The Problems &Solutions are Technical
  • 30% of the improvement comes from technical changes
    • Process changes
    • Tool changes
    • Changing rules and operations
most of the problems solutions are not technical
Most of The Problems &Solutions are Not Technical
  • 70% of the improvement comes from organizational and people changes, such as
    • Education
    • Communication
    • Management
    • Teamwork
slide155
Independent Observers See Problems and Opportunities the Best
  • Practitioners generally focus on their work and on what they THINK is happening rather than on what IS happening
    • They tend not to see all of the waits, queues, etc. that they cause themselves
    • Their perception of how they spend their time is generally incorrect
    • They are too busy getting the job done to see how they might improve it
slide156
The Athletic Coach Analogy
  • Just as athletes rely on coaches, software engineers need to learn to trust in others to observe and help them do better
software developers are accustomed to improving cycle time
Software Developers areAccustomed toImproving Cycle Time
  • Think of your software development process as a large computer program that runs too slow.
    • How would you make it run faster?
    • Imagine how you would speed up a computer program . . . . . . . .
    • Then draw analogies to the software development process
improve the process the way you would speed up a program
Improve the Process the way you would Speed Up a Program

Code Speed-up

  • Faster hardware
  • Better algorithm
  • Optimizing compiler
  • Remove code from inner loops
  • Optimize code
  • …..

Process Speed-up

  • Faster hardware
  • Better process
  • Eliminate waste
  • Remove redundant steps
  • Eliminate wasteful meetings and approvals
  • …..
slide159
CycleTimeBonus

It generally turns out that improved cycle time produces lower costs and higher quality as well!

You don’t pay for the steps you don’t do

  • Fewer steps means fewer opportunities to introduce defects
  • Shorter cycles means less time to change requirements
  • Shorter cycles means more time to iterate designs or benefit from cycles of learning
examples of software cycle time techniques
Examples ofSoftware Cycle Time Techniques
  • “Just-in-time” training
  • Plan testing and test equipment well in advance
  • Rethink the detailed design process
    • Do you need to maintain detailed design documentation?
    • Do you need to do detailed design at all?
  • Use on-line requirements and design models instead of paper documents and specifications
examples of commonly found software cycle time barriers
Examples of Commonly FoundSoftware Cycle Time Barriers
  • Poor communication/cooperation between software development and the rest of the organization
  • Poor management of unstable requirements, algorithms and interfaces
  • Contention for test assets -- need better planning, assets allocated to software test
  • Poorly qualified software subcontractors
more commonly found software cycle time barriers
More Commonly FoundSoftware Cycle Time Barriers
  • Excessive paperwork, signatures, and reporting
    • Negotiate reductions with management and customer
  • Reuse of software not designed for reuse
  • Attempts to use the latest tools and methods -- without adequate support and integration
summary1
Summary
  • Measure cycle time
  • Measure rework
  • Use these to show the value of process improvements
  • And to convince others that your techniques are worthwhile
    • Because many cycle time improvement techniques are “counterintuitive”

Focussing on cycle time can make the whole process more efficient, and effective

references2
References
  • Deming, W. Edwards, Out of the Crisis, MIT Press, 1982.
  • Goldratt, Eliyahu M. & Jeff Cox, The Goal, (North River Press, 1984.) Also, Theory of Constraints, It’s Not Luck, and Critical Chain Management.
  • Gross and Harris, Fundamentals of Queueing Theory (Wiley).
  • Swartz, James B., The Hunters and the Hunted, (Portland, Oregon, Productivity Press, 1994) ISBN 1-56327-043-9.
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