PMI ACP Quiz 14

Although usability of the product is one of the five (5) parameters that make up fitness to use, it is not a result of breakdown and repair. It is availability that is the result of how often breakdowns occur and how fast repairs are done. The three (3) other parameters are product quality, conformance to standards, and safety.

The Pareto chart is used to show that 80% of frequently occurring problems in a system can be traced to only 20% of distinct problems. It is a histogram designed in a descending order to show the distinct problems according to how frequently they happen. The Pareto chart is named after the Italian economist Vilfredo Pareto but it was popularized by Joseph Juran.

The 80-20 rule states that 80% of problem occurrences can be linked to only 20% of the distinct problems. In the above scenario, if there are 100 problem occurrences, 80% of this is 80. Since there are 10 distinct problems, then 20% of this is 2. Hence by the 80-20 rule: for every 100 problem occurrences of which 10 are distinct problems, 80 of the occurrences can be linked to only 2 distinct problems.

Joseph Juran popularized the Pareto chart which has become a guide for agile teams to focus on the most crucial features and uses of the product. Joseph Juran also shifted the attention to customer satisfaction, giving it higher priority over adherence to a plan or over the goodness of a product.

DRIFT is a principle formed by Philip Crosby which means doing it right the first time. He firmly believed in the idea that assignable cause can be prevented to the point of zero defects. Agile groups believe in the DRIFT principle although they prioritize fixing defects depending on customer feedback.

Sampling in agile project management gives more focus to inference statistics instead of descriptive statistics. Instead of relying on big data or extensive data measurements to prove conditions, it recognizes inferred conclusions based on facts that are much less than big data. These inferred conclusions are a product of an assessment of similar or closely related facts.

The 80-20 rule explains that 80% of all problem occurrences can be attributed to only 20% of the distinct problems, and vice versa. In the situations presented above, only one is not consistent with this description. If there are 100 problem occurrences, 80% of this 100 is 80. Since there are 30 distinct problems, 20% of this 30 should be 6 (not 20). Hence by the 80-20 rule: for every 100 problem occurrences of which 30 are distinct problems, 80 of the occurrences can be linked to 6 distinct problems.

Inference is the result of an assessment of closely related facts. It is an assumption of what is true about a specific condition without having to rely on large piles of data. An inference is created along with a statement of confidence about the certainty of a conclusion.

The use of inference statistics may be seen in cases where opinions of only a few represent those of the majority within a reasonable margin of error. The size of the sample also need not be specific to get a good outcome. In the examples above, the online votes may come from only a few and yet the result would be viewed as a representation of the majority: that a specific person is the sexiest man alive in 2020 because he got the highest number of votes. Meanwhile, the other examples require specific sample size to get a good outcome.

Defined limits, also referred to as defined process control, provide guidance on what the process should be and what a defect is. They are observed in process control charts. It is presumed that any product defect has already been studied with customers so that its unacceptability cannot be challenged.

According to Philip Crosby, the cost of quality is free. Instead, the cost of nonconformance is the add-on because the cost of conformance is just the cost of operating your business the proper way. Crosby also created the DRIFT principle which means doing it right the first time.

Six Sigma is a management practice popularize by W. Edwards Deming that points out and minimizes error sources in a defined process control. It is a problem-solving methodology as well as a glitch control strategy.

In Six Sigma, the control limits are set up in such a way that production produces less than approximately 3.4 defects in one million opportunities either above or below the control limits. This number is based on the possibilities of defect within six standard deviations of a bell-shaped curve, after giving it an allowance of 1.5 standard deviations drift of the rate of long-term average defect.

Ken Schwaber, in his objection to defined process control, pointed out that whenever defined process control cannot be attained due to complex intermediate processes, the empirical process control must be used. This is because defined process control is dependent on processes that work only because their level of imprecision is acceptable.

Empirical control aims to address defects that cannot be restricted within predefined error limits. Although it is based on observed facts, it evolves to fit the situation and is not confined to previously established limits during previous projects.

To “act” in W. Edwards Deming’s PDCA cycle means to act on the results of the measurement. This means that, first, you have to learn from the outcomes of the result – and then act on it. You then give feedback for corrective measures to the next iteration of the plan.

PDCA is deemed as the most significant contribution of W. Edwards Deming in agile project management. He adopted this style from Walter Shewhart which basically means to plan, do, check, and then act. Planning refers to envisioning what needs to be done, doing is executing the plan, checking is to measure the results, and acting means to learn from the results and provide feedback for corrective measures.

Six Sigma was not formed for projects and software. It is not agile as its processes are based on extensive documentation and it is also one of the greatest examples of defined process control. The error rates promoted by Six Sigma are far from what occur in projects and software. However, Six Sigma has attributes that can be applied to agile projects.

Six Sigma practices that are considered helpful to agile projects are problem identification, solution design, and opportunity space. Despite Six Sigma being not agile in itself, these attributes are highly suitable for managing agile projects. In Six Sigma, problem identification and solution design involve checking on the product outcomes and doing root-cause analysis to discover defect sources. Opportunity space refers to that where quality measurements are conducted for the continuous improvement of the product. These are very much in line with agile methods.

“Follow defect” in Six Sigma means to study the product outcomes and work back via root-cause analysis to discover defect sources. Six Sigma refers to this method as DMAIC (define, measure, analyze, improve, and control). This is a problem identification and solving method that actually utilizes the “check-act” component of W. Edwards Deming’s PDCA on a more advanced level.

The opportunity space in software systems is unique to the nature of the software. It can be made more difficult by how complex the software is. The opportunity space is sampled after iteration and is filled with defects that are known, unknown-but-knowable, and knowable.

Unknowable defects are defects that manifest from unlikely conditions. They also arise from conditions that only the user can identify once the product is already in an operational situation.

All defects may be fixed in the iteration in which they are discovered. They may or may not be fixed depending on priority and economics. It must be noted that known defects are those that are already known and are in a backlog. Unknown-but-knowable defects are those that are yet to be discovered.

In Six Sigma, statisticians make use of the standard deviation of the mean value of an unsecure process to evaluate errors. A lower deviation means lower uncertainty in the process, which also means a lower number of errors created outside of a process quality limit. This standard deviation is denoted by the Greek symbol “σ” which is called (lowercase) sigma.

Unknown-but-knowable defects are not yet known but can be discovered following testing. This process of testing and discovery is however subject to priority and economics. Fix for some defects may be delayed while others may not be addressed at all depending on these factors. But majority of the errors will be addressed in the iteration in which they are observed.

Six Sigma’s principle of DMAIC (define, measure, analyze, improve, and control) is highly supportive of agile methods. This does not need to invoke all other aspects of Six Sigma which are contradictory to agile principles. Six Sigma as a whole is not agile and it was not formed for projects or software. But it has attributes – the DMIC for one – that benefits agile projects.

When hybrid operating principle is used, agile projects become strategically stationary as well as tactically iterative and emergent at the same time. This means that the strategic intent remains all throughout however you look at the business. Teams are however given flexibility to evolve processes in order to address issues.

In the context of hybrid operating principle, “strategically stationary” means that the strategic intent and vision of the business remains the same however way you look at it – whenever and wherever you look. Strategic intent is the expression of the business regarding the opportunity and vision of the project. It is the expected result also expressed as the mission.

When agile projects are tactically iterative and emergent, it means that groups are granted flexibility to address problems locally. Instead of adhering to established processes, they can actually evolve processes in order to be lean, fluid, and efficient. They are also encouraged to meet the specific demands of the customer so long as they do not deviate from the strategic intent.

The project charter always considers some risks to the objectives of the project. These risks include those which are not clearly covered in the business case and even those risks that are adverse to the optimism of the business case. To best address these risks, the business has to be tactically emergent and iterative.