Is a Prediction Model Required for Maturity Level 4

Is it necessary to have a prediction model for L4 and L5?

I collect data from different projects and put them in a 3 sigma band and take care of outliers.  Then I compare the mean and standard deviation of current PBB with previous PBB.  And I also check against the LSL and USL set by the management team the trend coming out of this PBB.  In case the mean, SD, LCL and UCL decrease from the previous PBB, I update the management team and we check the projects on the basis of this.

What happens when I talk to someone in my circle of friends they talk about regression, simulation, Monte Carlo, etc.  In my organization we need to show process performance against set targets, so why make life so complex with so many above mentioned methods?


From what I can glean from your question is that you have developed a Process Performance Baseline (PPB).  But I have no idea why you have done this and what value you are getting from knowing this PPB.  What use is it to your organization?  How does it help you meet your Quality and Process Performance Objectives (QPPOs) and your business goals?

If you are not interested in fully implementing ML 4 or ML 5, then I suppose you don’t need anything else as long as you are deriving some sort of benefit from this PPB.  However, for a complete High Maturity implementation, you are expected to do the proper statistical analysis of data distributions, probability statistics, process engineering, etc. to derive appropriate PPBs and PPMs.  And to be a PPM instead of merely a forecast model and be of use for "what-if" analyses, the PPMs must contain controllable factors that have an impact on the outcome.

Also, if you want to implement ML 4 and/or ML 5, then you need to have established organizational QPPOs, a number of PPBs that support the QPPOs and can be used to evaluate the feasibility of achieving them, and a set of Process Performance Models (PPMs) that are derived from your historical data that are used in conjunction with the PPBs to predict each project’s ability to meet its QPPOs, as well as a number of other activities.

Therefore, if all that you have is one PPB and nothing else, you only have a partial implementation of OPP and still have a lot of work ahead of you before you can consider that you have implemented ML 4, let alone ML 5.

Is This a Valid Performance Model?

Is a reliability growth model considered to be a valid PPM in the CMMI?


Asking this question out of context with what you do in the organization does not have a lot of meaning.  The correct answer is both yes and no.  Please remember what High Maturity is all about.  You begin with setting your business goals and objectives and use them to derive your Quality and Process Performance Objectives (QPPOs).  These QPPOs in turn will lead you to the proper measures, process performance baselines (PPBs), and process performance models (PPMs) that your organization needs to quantitatively and statistically manage your work.So, if Reliability Growth is a critical process or sub-process and you have sufficient data to analyze to determine that you have a stable and capable process, then a reliability growth model might be considered a valid PPM.

But just selecting models without performing the analysis I just sketched out is incorrect and you will not be able to demonstrate that your organization is a High Maturity organization.

Thanks for the detail. I just happen to see in CMMI v1.3 High Maturity in which the "reliability model growth" which was given as example in OPP SP1.5 (CMMI v1.2) is deleted. Does it mean that reliability growth model will not be accepted in CMMI v1.3? Or the reliability growth model is not acceptable by the experts? Or is it only good if you use CMM v1.2  and not for CMMI v1.3?

As CMMI v1.3 is an improvement and the practices are carefully analyzed by the SEI and experts, is it advisible to use the reliability growth model given in CMMI v1.2? Or there is any chance that CMMI v1.3 will include the reliability growth model as an example?


Apparently there is some misunderstanding of my answer above.  Whether the CMMI contains the reliability growth model as an example or not is irrelevant to whether or not it is a good model.  Your organization has to mathematically analyze its data, business objectives, QPPOs, PPBs, and PPMs to determine if there is a need for using a reliability growth model.  Do the following analysis:

1. Describe the reliability growth model in probabilistic terms.
2. Define the critical sub-processes (those that must be consistently and correctly followed every time) that can be managed using the reliability growth model.
3. Define how a project manager uses the reliability growth model in the context of his or her projects to predict performance, "what-if" analysis, and predict QPPO achievement.
4. Provide an equation or show by other means how the stable sub-processes that you have identified in your processes contribute to the reliability growth model.
5. List the other models that are used in conjunction with reliability growth model and why it has statistical relevance.

Once you have performed this analysis you will have enough information to answer this question yourself.

Rationale for Maturity Level 5

Our organization is currently at Maturity Level 3 and is now planning to go for Maturity Level 5. Our CEO is asking for the short term and long term benefits and challenges for implementing Maturity Level 5. How do we provide this information?

The question that needs to be asked is why does your organization want to achieve Maturity Level 5 (ML 5)? If the organization has already achieved Maturity Level 3 (ML 3), what is the motivation for achieveing ML 5? Most likely it is not mandated in a contract or by its customers. But achieving ML 5 is desirable to be competitive in the marketplace. Therefore, the reasons for achieving ML 5 should provide some indication of the short term and long term benefits.

The first step in becoming a High Maturity organization is defining your Quality and Process Performance Objectives (QPPOs) that are based on your business goals and objectives as well as your customer needs. The QPPOs should be stated in a form such that they specify a timeframe. And that information will provide some ideas of the short term and long term benefits.

However, the best advice that I can provide is to hire an SEI-certified High Maturity Lead Appraiser (HMLA) who will work with you to help explain the benefits of ML 5 to the CEO. The HMLA should have experience working with many different organizations at various Maturity Levels and be able to talk about the different challanges that have been faced by other organizations, as well as the challenges and risks within your organization.

At this point, it sounds like your organization is just beginning its journey to ML 5, so I would have to be convinced that your processes are stable enough to provide the data needed to quantify any short term and long term benefits. I think that the best you could do at this point is communicate this information in qualitative terms. Any quantitative information may not be accurate until you have implemented High Maturity.

Auditor Directing a PPM

We are trying for CMMI ML 5 Ver 1.2, and our auditor has asked us to come up with a PPM for predicting the outcome of CAR and OID. Can you help me on how to go about it?

When you say auditor, I assume that you mean your Lead Appraiser (LA) is asking you for a PPM for predicting the outcome of Causal Analysis and Resolution (CAR) and Organizational Innovation and Deployment (OID). Is your Lead Appraiser an SEI-certified High Maturity Lead Appraiser? Has your organization identified the need for a Process Performance Model (PPM) to predict the CAR and OID outcomes, or is this solely a request from your LA? Your LA is not the person to tell you which PPMs you need. Do you have Process and Product Quality Objectives (QPPOs) that require PPM(s) to predict CAR and OID outcomes? If the answer is no, then you don't need a PPM for CAR and OID.

What I find odd is that you do not mention a Process Performance Baseline (PPB) for CAR and OID. If you are going to define and develop a PPM, then you really need to develop the CAR and OID PPBs first before you can determine the PPMs. From your brief description, it sounds like your Lead Appraiser may have overstepped his boundaries in asking for the CAR and OID PPM.

PPM - Data Analysis

We are a CMMI ver 1.1 level 5 assessed software company and we are in the process of ver 1.2 assessment. As part of this, we are developing the Process Performance Models. We would like to get input on the following points.

1. What kind of statistical analysis are required on the data that is collected for the PPM development?.
2. Do we need to perform Gage R&R test on the data that is collected?. As mentioned, since we are a software company and not a manufacturing company, i am not too sure about the data collection that needs to happen at multiple instances by the same person on the same tool and different person on the same tool.

For example, to check for Repeatability, if I am considering Schedule Variance of various feature development as a measure, there might not be any difference in the schedule variance that will be measured by different people, if the operational definition is clear for the metric.
Now to check for Reproducibility, if competency of the resource for code development is considered as a measure, this could be changing from period to period, as unlike in manufacturing industry where the activities are of repetitive nature. So the reproducibility will be minimal in this scenario.
If its mandatory to perform Gage R&R analysis on the data, can you throw some ideas on the different areas where this can be applied and how the analysis can be performed. Please share your thoughts on this.

It sounds like the Process Performance Models (PPMs) were overlooked for your organization when it was appraised to CMMI v1.1 3 years ago. I would like to make several points regarding PPMs.

1. The CMMI does not specify any required statistical analysis technique for PPM development. Based on your data, your QPPOs, PPBs, the organization has to decide the proper analytic techniques to use. There is a wide variety available for use.
2. What is the reason you are considering Repeatability and Reproducibility? Are you led to these items by your Quality and Process-Performance Objectives (QPPOs)?
3. There is no CMMI requirement to use Gage R&R.
4. It sounds to me that it would be a good idea for you and your organization to have someone facilitate a Measurement and Analysis workshop for you to properly identify your measures, PPBs, and PPMs.
5. You are asking some questions that cannot be properly answered on this blog unless we are working directly with your organization and have some knowledge of your business.

Difference between measurement objectives and process performance objectives

CMMI uses following terms while talking about measurements:

1. Identified information needs and objectives at organization level (MA)
2. Measurement objectives derived from such information needs and objectives (MA/SP 1.1)
3. Quality and Process Performance Objectives (OPP/SG1)

I want to investigate finer differences between the later two. Are they more or less the same? If not, what are the finer differences?

Your first two questions deal with Measurement and Analysis (MA) which is a Maturity Level 2 Process Area (PA). Your third question is about OPP which is a Maturity Level 4 PA.
MA is a support PA that applies to ALL PAs in the CMMI. Its focus is defining measures and indicators that help answer or address a specific information need. An information need can be articulated using the following format:

<someone> needs to know <what information> in order to make <what decision>.

For example, an issue facing the Project Manager may be that Project Plans are inaccurate causing project teams to routinely miss milestones and deliveries.
Therefore the information need would be: The Project Manager needs to evaluate the schedule, progress, and dependencies of key development activities and events in order to determine necessary corrective actions.
Then the measurement concept or strategy for addressing this information need would be: At the end of each week the Project Manager collects estimates to complete the work for each current task and enters the data into the schedule. The Project Manager and team review progress to determine the necessary corrective actions and modify the Project Plan as needed each Monday morning.
Now it becomes very easy to determine the base and derived measures that support the measurement concept.

So these concepts (information need, measurement concept, and measures) are interrelated concepts that help define what data to collect and analyze to help answer a question.

The Quality and Process Performance Objectives (QPPOs) are entirely different from the measurement concept. The QPPOs are objectives set by the organization based on the organization’s business objectives, past performance of projects, and are constrained by the inherent variability or natural bounds of the process. Now, in order to determine the measures that the organization will use to support the QPPOs, the organization should follow the MA process of articulating the information need, defining the measurement concept, and determining the measures.

Understanding How Project Planning Evolves from ML 3 to ML 5

The primary difference between project planning at Maturity Level 3 (ML 3) and Maturity Level 5 (ML 5) is how you construct the project’s defined processes. At ML 3 a new project starts from the organization’s set of standard processes and applies the appropriate tailoring criteria or guidelines for the project, based on the project requirements. At Maturity Level 4 (ML 4) and ML 5 a new project first has to define what its quality and process performance objectives are based on the organization’s quality and process performance objectives (QPPOs). Then the project looks at the organization’s set of standard processes and selects the processes or sub-processes that are capable of being quantitatively and statistically managed to achieve the project’s QPPOs using the established Process Performance Baselines and Process Performance Models. These processes and sub-processes are selected based on historical stability and capability data along with the appropriate tailoring guidelines and criteria to construct the project’s defined process.

Definition of Complexity

While going through some SEI Presentations, I came across a term Design Complexity which was one of the contributing factors for the Delivered Defect Density. As we have chosen this as one of the PPMs in our organization, I would like know how to define the "Design Complexity". I have been searching in Google for the definition, but unable to find it.

I see a problem right from the start in your approach. You have elected to use a term and build a Process Performance Model that has no definition within your organization. Don’t do a literature search to determine what Process Performance Baselines (PPBs) and Process Performance Models (PPMs) to build for your organization. You need to start from the basics. What are your organization’s Quality and Process Performance Objectives (QPPOs)? You need to determine these first. Then you analyze the data in your measurement repository to build PPBs and PPMs that support the QPPOs.

The next step to use Measurement and Analysis (MA) to take the QPPOs, derive the information needs for the QPPOs, and then the measurement specifications that support the information needs and QPPOs. Once you have performed the MA process for your QPPOs, then you will be able to determine if you in fact need to look at Delivered Defect Density and/or Design Complexity. And keep in mind these two terms are just labels. The data you collect and analyze for Delivered Defect Density in one organization may be different from the data for Delivered Defect Density that are collected and analyzed for a different organization. The concepts are important, but going through the MA process will help you define what you need for your organization. Then you can apply whatever label makes sense for you. The MA process will also focus you on what data to analyze to build the PPBs and PPMs that will support your QPPOs.

Obviously Delivered Defect Density and Design Complexity are interesting things to look at, but do they support your organization’s QPPOs? If not, then there is no point in investigating them any further.

Now having said all that, I am surprised that you haven’t been able to locate any information on Design Complexity on the internet. In fact here is an SEI link on this subject http://www.sei.cmu.edu/str/descriptions/cyclomatic_body.html and a Wikipedia definition http://en.wikipedia.org/wiki/Cyclomatic_complexity

Tom McCabe has developed a whole collection of complexity measures, which you find out more about here http://www.mccabe.com/

Bottom line, work through the OPP and MA processes first, THEN look for help with definitions and building PPBs and PPMs. Don’t adopt someone else’s PPBs and PPMs just because these worked for them.

Help! I am Totally Lost When Interpreting the QPM Specific Practices

QPM SP 1.1 states “Establish and maintain the project’s quality and process-performance objectives.” When you are starting to implement the Maturity Level 4 PAs you won’t have a Process Capability Baseline, that is ultimately the goal of being at ML 4 so the organization can then move to ML 5. One of the main thrusts of ML 4 is to analyze the process data looking for Special Causes of Variation. Once those have been analyzed, then it is possible to determine the process capability. For SP 1.1 the project’s quality and process-performance objectives (QPPOs) are set by management and are based, in part, on the organization’s objectives (OPP SP 1.3). The Process Performance Models (PPMs) are then used to determine if the QPPOs can be met. If not, the QPPOs should be appropriately adjusted.

QPM SP 1.2 states "Select the sub-processes that compose the project's defined process based on historical stability and capability datat." One of the key words in this practice statement is "historical". Sources of historical stability and capability data include the organization’s process performance baselines (PPBs) and PPMs (OPP SP 1.4 and SP 1.5). And the intent of this practice is to tailor the organization’s standard processes (OSSP) so the project’s processes will support the project’s QPPOs defined in SP 1.1.

QPM SP 1.3 states “Select the sub-processes of the project’s defined process that will be statistically managed.” The model does not say that these sub-processes MUST be statistically managed, but these WILL be statistically managed. And this practice focuses more on than just selecting sub-processes. It also focuses on identifying the attributes of each sub-process that will be used to statistically manage the sub-process.

People appear to get confused with Maturity Level 4 (ML 4) sounds when trying to understand QPM independently from the rest of the model. You cannot do that. You have to consider OPP and QPM together when looking at ML 4. OPP provides the analysis of the historical data to build the PPBs and PPMs which are then used by the projects to help them appropriately tailor the OSSP to what will meet the project’s QPPOs. QPM SP 1.2 uses the word "compose", which may contribute to some of the confusion. Since compose is not in the CMMI Glossary, then the dictionary definition is applicable. The Webster definition of compose is “To form by putting together two or more things or parts; to put together; to make up; to fashion.” So for this practice, compose means going to the OSSP and selecting the processes and sub-processes that will meet the QPPOs and then applying the necessary tailoring criteria. What this practice implies is that the OSSP may have several different processes for each Process Area (PA) so the project manager can choose the most appropriate one when composing the project's defined process.

Another ML 4 concept that may be the cause of confusion is the notion of Quantitative Management vs. Statistical Management. QPM SG 1 is all about quantitatively managing the project, which means the Project Manager must be periodically reviewing progress, performance, and risks using the PPMs to determine/predict if the project will meet its QPPOs. If not, then appropriate correctives actions must be taken to address the deficiencies in achieving the project’s QPPOs (QPM SP 1.4) Statistical Management is covered by QPM SG 2. The intent is for the project to statistically manage those sub-processes that are critical to achieving the project’s QPPOs. There are only a small set of sub-processes that are critical to achieving the project’s QPPOs. If the organization were to statistically manage all processes, that would be insane. This approach would mean that the organization would need PPBs and PPMs for EVERY process, regardless of their importance to the QPPOs. And then the shear overhead of collecting, analyzing, and reporting data on every process would most likely bring the organization to its knees. Work would come to a standstill because it was taking far too much time to statistically manage each process and taking corrective actions that may not be necessary. Unless you have an infinite budget and dedicated staff to perform these analyses, that is why the model states to statistically manage SELECTED sub-processes.