Six Sigma definitions

Some Six Sigma definitions which I’ve collected over time.

Term Definition
CTQs Critical To Quality.  The sort list of the most important customer wants.
Customer Any internal/external person/organisation who receives the output of a process.
Customer Requirements The needs and expectations of the customer.  Which is translated into measurable terms.  Used in the process to ensure compliance with customers’ needs.
Defect Any occurrence or instance where the product/service fails to meet the customers requirements.
Defect opportunity A type of potential defect on a unit of throughput/output, which is important to the customer.
DPMO Defects Per Million Opportunities.  Calculation used in process improvement initiatives indicating the amount of defects in a process.
Sigma A statistical term that measures how much a process varies from perfection, based on the DPMO.
Six Sigma A level of process performance equalling 3.4 DPMO.
Standard deviation Statistical measure of how much variation there is in a set of data.
Variation Change/fluctuation of a specific characteristic.  Determines process stability/predictability.

Bookmark and Share

Let’s really shoot ourselves in the foot.

There was a discussion at work the other week about system availability measurements.  We’re aiming for “Five Nines”.  Noble target, doubt we’ll achieve it though, without some clever availability exclusions.  I’ve mentioned those exclusions before.

Availability %

Downtime per week Downtime per month* Downtime per year


16.8 hours 72 hours 36.5 days


8.4 hours 36 hours 18.25 days


3.36 hours 14.4 hours 7.30 days


1.68 hours 7.20 hours 3.65 days


50.4 minutes 3.60 hours 1.83 days


20.16 minutes 86.23 minutes 17.52 hours

99.9% (“three nines”)

10.1 minutes 43.2 minutes 8.76 hours


5.04 minutes 21.56 minutes 4.38 hours

99.99% (“four nines”)

1.01 minutes 4.32 minutes 52.6 minutes

99.999% (“five nines”)

6.05 seconds 25.9 seconds 5.26 minutes

99.9999% (“six nines”)

0.605 seconds 2.59 seconds 31.5 seconds

Table courtesy of Wikipedia – High Availability.
* For monthly calculations, a 30-day month is used.

Bookmark and Share

A Project Manager’s Guiding Principles

  • Lead by example
  • Constantly communicate a sense of urgency
  • Know your scope, manage it relentlessly
  • Report the past – Manage the future
  • Know your governance model and use it appropriately
  • Keep on track with the weekly control cycle
  • Manage your stakeholders proactively
  • Escalate high-priority issues early
  • Keep your focus on the end game
  • The plan is your map, ensure you know where you are

(source: unknown)

Bookmark and Share

Project Landmines

  • Poor project definition
  • Ineffective project management
  • Ineffective architectural engineering
  • Poor communications
  • Inadequate project plan
  • Inadequate project tracking and projecting
  • Ineffective governance
  • Lack of client alignment and support
  • Lack of accountability
  • Ineffective scope control

Bookmark and Share

This week’s work challenge? – Project Managers!

Project Management - Much work remains remains to be done before we can announce our total failure to make any progress. Project Managers are those people who “”manage”” projects.

Sort of like a “stay at home” mum who organises her children’s day. Except the mum is competent, and the project manager isn’t.

Competency is an interesting sideline in itself. If someone isn’t competent, does that automatically mean that they are incompetent?

Actually no. In “training speak”, they are not yet competent. Sort of like how “deferred success” is the new phrase for “failure”.

Where was I?

Ah Project Managers! I’m working with/guiding four of them at the moment.

The competency ranges from: “oh my gawd, how do you manage to tie your shoes laces?” to “able to form five-word sentences in a single bound”.

The projects being managed are all doing the same thing for different customers, so it will be interesting to see which of the biggest losers will succeed. I’m tipping the cute (female) project manager, as she has nouse.

We trained very hard, but it seemed that every time we were beginning to form up into teams we would be reorganized. I was to learn later in life that we tend to meet any new situation by reorganizing–it can be a wonderful method of creating the illusion of progress while creating confusion, inefficiency and demoralisation.

Actually that fellow should work where I do. Two phrases which stop most work requests before they hatch?

“That’s not part of my job description”

and if that fails

“Do you have an expense code for me to charge my work against?”

It’s been that kinda week. Playing a piano in a brothel would be more honest work.

Bookmark and Share

Bits and Pieces – Project Management

Post Implementation Review

A lot of time, money and energy went into the "project". At times things were difficult but the result was a quality deliverable.

But at the end of the day the thing that most impressed the users bore no resemblance to their original requirements.

85 miles there, 85 miles back, a severely depleted budget and all they want to do is chase an artificial turd down a pipe.

Frankly if you don’t think this is a good analogy for software development then I don’t know what is!

The Lighter Side – Life is like an analogy (David Poole talks about the software development process)


Bookmark and Share 

Some notes on Project Management – Part 3 of 3

Scheduling tools & techniques

  • Mathematical analysis
  • Duration comparison
  • Simulation
  • Resource leveling heuristics
  • Project Management Software
  • Coding Structure

Mathematical analysis

  • Critical Path
  • PERT
  • GERT

Critical Path
is where the path has the minimal float over the longest path
To calculate this, need duration of each task
Task Duration equals = Early Finish – Early Start or Late Finish – Early Finish

estimating requires the following three things:

  • TM = Time – most likely estimate to complete
  • TO = Time – optimistic
  • TP = Time – pessimistic

To calculate the expected activity time:
(TO + 4xTM + TP) / 6

Bookmark and Share

Some notes on Project Management – Part 2 of 3

Project Cost Estimation

Benefits of understanding cost estimating

  • Will use methods which fit project.
  • Cost estimates will be as accurate as possible
  • Calculate estimates more quickly

Cost Benefit Issues

Cost Benefit
Time to gather information High level of accuracy
High salaries required to hire experienced and knowledgeable staff Quickness
Purchase of estimating software Quicker estimating with more accurate results
Risk of less accurate estimates Saving time & money by using estimates for similar projects

Inputs to Cost Estimating
Four sources of historical info:

  • project files
  • project team knowledge
  • commercial cost-estimating databases
  • estimating publications

Three types
1. Analogous estimating
– also known as "top down"

  • less costly to estimate using this method
  • it is less accurate

It is of benefit when:

  • new and previous projects are similar
  • individuals doing the estimate have the expertise
  • estimating team has adequate information about the previous project(s).

2. Parametric model
– also known as formula based

Can use this when:

  • project has quantifiable parameters
  • the parametric model is scalable
  • accurate historical data has been used to develop an appropriate model.

Parameters of project must be quantifiable to use this method.
The parametric model must be scalable as well.

3. Bottom Up

Activity Duration Estimates

  • include a range of results
  • convert units of time to a common units (ie. hors)
  • allow for down time (ie. holidays etc.)

Estimating costs for estimate

  1. Establish the activity duration estimate
  2. Check the resource rates which apply to the activity
  3. If necessary, convert unitis of time
  4. Multiple the estimate duration by the rate for the activity.


Project Cost Estimation: Six Inputs

The six inputs are:

  1. Work breakdown Structure (WBS)
  2. Resource requirements and rates
  3. Corporate chart of accounts
  4. Activity duration estimates
  5. Historical information and workflow
  6. Risks

Work Breakdown Structure

  • organises your cost estimates
  • identifies each project activity which generates cost
  • be able to represent your project in a graphical form.

Decomposition of WBS

  1. identify major elements of the project
  2. decompose elements into tasks, work packages and detailed activities
  3. lowest level items are tangible and can be measured. <- THIS IS THE MOST IMPORTANT STEP
  4. Verify completeness by having someone review it.


Bookmark and Share

Some notes on Project Management – Part 1 of 3

Just some notes I made on Project Management, over time …

Project: Risks

Risks can be categorised into:

  • predictable
  • unpredictable
  • technical
  • non-technical
  • legal

Project: Resources

Resource requirements are generally one of the following five:

  1. Labor
  2. Material
  3. Equipment
  4. Overhead costs
  5. Contingency costs

Resource rates examples:

  • staff costs per plan
  • paper costs per copy
  • printing costs per copy
  • lease costs per day
  • interest costs per year
  • component costs per part

In Project definitions

We don’t:

  • "ensure" or
  • warrant or
  • certify or
  • guarantee


Bookmark and Share