The Differences Between CMM And CMMI

The recent attitude of the organisations to make the products complex in order survive the competitors, made them to employ software in their organisations. However, the community of information systems known for its poor product quality made them to research the methods to improve its efficiency. This led them to discover that the focus was needed more on the processes which in turn led to improve the quality of the software products. The process when used it an efficient way can make the organisations maintain the consistency and help to achieve their mission. Many models and programmes described the ways to improve the product quality. Of those, The Capability Maturity Model (CMM) found by SEI, in 1984, gave a clear sight to the organisations the efficient way to improve the process. Later, it was found that it can be employed in other fields too and thereafter it was employed to improve business processes. However this method had some drawbacks and those were superseded by the Capability Maturity Model Integration (CMMI). This essay portrait the key differences between these models and describes the effectiveness of using CMMI.

2. Differences between CMM and CMMI

2.1 CMM Overview

The first CMM, developed in 1990, was developed for the purpose to improve the process in software development [1]. This model proved to be a successful one and thereof, it became a generalised model for improving the processes other than SW development process like software engineering, system engineering,

software maintenance, software management, risk management and also being employed in other industries, governments, organisations and also for business process improvement [1].

Fig.1 CMM Maturity Levels [2]

The CMM for Software (SW-CMM) is a framework that provides the way to manage a process effectively. It is a stair-cased structure wherein each step is a maturity level describing the current capability of the process. It tells where the processes are. The CMM scales the organisation from 1 to 5 based on the KPAs achieved by the organisations.

Fig. 2.2 Structure of the CMM [3]

As shown in the figure 2, each maturity level defines the process capability at that stage and contains (other than Initial) Key Process Areas (KPA) defined of goals to be achieved. Each KPA has certain key practices that are to be strictly followed to achieve the goals. These key practices are arranged as groups (Common features) consisting infrastructure and implementation.

2.2 CMMI Overview

“CMMI is a process improvement approach that provides organizations with the essential elements of effective processes that ultimately improve their performance. CMMI can be used to guide process improvement across a project, a division, or an entire organization.” [4].

Both CMM and CMMI have the same five maturity levels. In CMMI, each process area has specific goals and generic goals that define the generic and specific practices respectively.

Fig.3.1 CMMI Structure [5]

There are two types of approaches — staged and continuous. In the case of the staged approach, KPA’s are defined and then based on it the maturity level structure is drawn whereas in the continuous approach, a specific KPA is chosen and then it is relatively improved by using the capability levels [6].

The CMMI too scales the organisation from a scale of 1 to 5 based on the KPAs. It also provides an appraisal which focuses on improving the plans for the organisations. There are three classes of appraisals, namely class A, B and C [7].

2.3 Key Differences

The factors that distinguish CMM and CMMI during implementation are: 1.integration, 2.KPA, 3.approach and 4.paperwork [8].

2.3.1 Integration: The CMM has individual models for each function. But when the individual processes when integrated led to few discrepancies like model overlapping, contradiction and each model had its own maturity level which lead to a confusion. This led to the increase in the costs of the companies that were put in training.

But CMMI employs models that are classified on the basis of specific areas of interests. These models are those employed by industries successfully. To employ CMMI in an organisation, it must choose a model form the available 22 models wherein each module covers all the functionalities.

2.3.2 KPA: Both CMM and CMMI have 5 maturity levels. But there are differences in the KPAs of each maturity level. The differences in each model are as follows:

1. Initial: In both models, it covers the organisations without defined processes, having dynamic changes (ad-hoc) and undocumented.

2. Repeat: In CMM, the companies that seem to do the same process periodically attain this level. In CMMI, it requires a planned and defined ways of managing the requirements by estimating cost, time and resources.

3. Defined: CMM requires a standard, well-documented and consistent process with few degrees of changes to be followed. CMMI requires the process to be standardised, methodical and procedural with the use of tools.

4. Manage: CMM requires companies to quantitatively measure and monitor process thereby reducing risks. CMMI, n addition identifies and monitors the sub processes that contribute to overall efficiency.

5. Optimized: In CMM, the process is continuously improved by following the best software engineering practices but here the measures are taken simultaneously as the goals are satisfied. In CMMI, behaviour is selected and goals are set to support it. Behaviour is selected on the basis of goals and measures.

2.3.3 Approach

CMM is an activity based model. It aims only in the completion of the process and does not care about the desired result and hence it does not motivate the company to make the necessary changes. But CMMI is a result oriented based on key performance areas and thereof it is a best practice for the companies and helps to avoid the possible risks at a very early stage.

2.3.4 Paperwork

Both CMM and CMMI documentation has paperwork and meetings that leads to waste of effort and time of the personnel. However, in CMM is process-oriented whereas the CMMI is a goal-cum-result-oriented approach.

3. Benefits of adopting CMMI

The organisations that adopted the CMMI reported the following benefits [9]:

3.1 Cost: The CMMI adoption led to reduced defect fix cost, reduced overhead rate, reduced cost of poor quality and increased the average cost performance index with decline in variation.

3.2 Schedule: It led to reduction in release turnaround time, reduction in average number of days late, increased percentage of milestones met, increased throughput that led to more releases per year, improvised and stabilised schedule performance index with decreased variance and increased time delivery accuracy.

3.3 Quality

Reduction in software defects (KLOC), errors caused in the source code and the post-release defects and increased focus on quality by developers was observed after using CMMI.

3.4 Productivity

Productivity was measured in metrics like number of statements produced per month, comparing the various builds, number of releases per year, software production etc, Productivity of the companies also increased.

3.5 Customer Satisfaction

The customer satisfaction, measured using ratings and awards fees, increased since the time of delivery mentioned was accurate and also it was defect free.

3.6 Return on Investment (ROI)

ROI ratio measured based on the defects that are overcome, the degree of automation activities and quality and process improvement, seemed to be on the positive side that motivated the organisations to employ CMMI.

4. Case Study of companies switching over to CMMI from CMM

The following three points are the detailed reports [10] of the companies that evolved from CMM to CMMI which depicts the improvements and results of doing so.

4.1 Lockheed Martin M& DS

Initially, the organisation was assessed CMM level 2 in 1993. But later, in 1996 it moved to CMM Level 3 and then evolved to CMMI Level 5 in 2002 in integrating SE-CMM and SW-CMM. As a result of this, improvements in the customer satisfaction, productivity and the product cost were noted leading to the conclusion that the process improvement that lasted for nearly 10 years proved fruitful. Between 1996 and 2002, process improvement was continual and the company increased its productivity by 30% and decreased unit software cost and defect costs by 20% and 15% respectively. The customer satisfaction was achieved as there was an increase in percentage of the available award fees [10].

4.2 Accenture

Accenture, one of the reputed organisations, had a transition from the SW-CMM to the CMMI between May, 2001 and May, 2002. It attained the CMM Level 3 initially and when they moved to CMMI, during which they acquired CMMI Level 3. During the CMMI, the organisation focussed mainly on the processes related to the Measurement and Analysis, Decision Analysis and Resolution, generic goals and Integrated Product and Process Development (IPPD). As a result of the transition, improvements in the costs of quality and ROI ratio were captured. The ROI ratio achieved was 5:1 in the quality [10].

4.3 Boeing Limited, Australia

The Boeing Limited process performance was not up to the mark. Initially they were using CMM and Electronics Industry Alliance (EIA 731). Thereof, they decided to improve the process by adopting CMMI so as to 1. Integrate SE and SWE 2.Universal acceptance by customers and suppliers and 3.Risk analysis using Defence Material Organisation (DMO) strategy. There were improvements seen in the product cost, schedule/cycle time and the product quality. The results of adoption made defect fix costs, turnaround time and test audits (pre and post) decrease by 33%, 50% and 60% respectively and product quality increase to a major extent [10].

5. Factors that have major impact

From the case studies it is clearly evident that the integration, approach styles and the need for continuous improvements of the process by the organisation led to the organisations to move from CMM to CMMI. However there are many organisations like Bosch Gasoline Systems, Thales Research & Technology, Sanchez Computer Associates Inc, still are using the CMM and reporting benefits thereof.

6. Conclusion

CMMI models should be still integrated and developed such the costs involved and the efforts are reduced.