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. |

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 |
|
90%
|
16.8 hours |
72 hours |
36.5 days |
|
95%
|
8.4 hours |
36 hours |
18.25 days |
|
98%
|
3.36 hours |
14.4 hours |
7.30 days |
|
99%
|
1.68 hours |
7.20 hours |
3.65 days |
|
99.50%
|
50.4 minutes |
3.60 hours |
1.83 days |
|
99.80%
|
20.16 minutes |
86.23 minutes |
17.52 hours |
|
99.9% (“three nines”)
|
10.1 minutes |
43.2 minutes |
8.76 hours |
|
99.95%
|
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.

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.

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)
Scheduling tools & techniques
- Mathematical analysis
- Duration comparison
- Simulation
- Resource leveling heuristics
- Project Management Software
- Coding Structure
Mathematical analysis
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
PERT
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
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.
Note:
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
- Establish the activity duration estimate
- Check the resource rates which apply to the activity
- If necessary, convert unitis of time
- Multiple the estimate duration by the rate for the activity.
Project Cost Estimation: Six Inputs
The six inputs are:
- Work breakdown Structure (WBS)
- Resource requirements and rates
- Corporate chart of accounts
- Activity duration estimates
- Historical information and workflow
- 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
- identify major elements of the project
- decompose elements into tasks, work packages and detailed activities
- lowest level items are tangible and can be measured. <- THIS IS THE MOST IMPORTANT STEP
- Verify completeness by having someone review it.

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:
- Labor
- Material
- Equipment
- Overhead costs
- 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
anything
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