Quality software should reasonably be bug-free, delivered on time and within budget. It should meet the given requirements and/or expectations, and should be maintainable.  In order to produce error free and high quality software certain standards need to be followed.

Software Quality:

Quality software should reasonably be bug-free, delivered on time and within budget. It should meet the given requirements and/or expectations, and should be maintainable.

In order to produce error free and high quality software certain standards need to be followed.

Quality Standards

ISO 9001: 2000 is Quality Management System Certification. To achieve this, an organization must satisfy ISO 9001: 2000 clauses (clauses 1 - 8).

Six Sigma is a process improvement methodology focused on reduction in variation of the processes around the mean. Its objective is to make the process defect free.

SEI CMM is a defacto standard for assessing and improving processes related to software development, developed by the software community in 1986 with leadership from SEI. It’s a software specific process maturity model. It provides guidance for measuring software process maturity and helps process improvement programs.

SEI CMM is organized into 5 maturity levels:

1. Initial
2. Repeatable 
3. Defined 
4. Manageable 
5. Optimizing

1)Initial

The software process is characterized as ad hoc, and occasionally even chaotic. Few processes are defined, and success depends on individual effort and heroics.

2) Repeatable:

Basic project management processes are established to track cost, schedule, and functionality. The necessary process discipline is in place to repeat earlier successes on projects with similar applications.

3) Defined:

The software process for both management and engineering activities is documented, standardized, and integrated into a standard software process for the organization. All projects use an approved, tailored version of the organization's standard software process for developing and maintaining software.

4) Managed:

Detailed measures of the software process and product quality are collected. Both the software process and products are quantitatively understood and controlled.

5) Optimizing:

Continuous process improvement is enabled by quantitative feedback from the process and from piloting innovative ideas and technologies.

Comparison of CMM and ISO

Features	CMM	ISO 9000
Assess process maturity	Yes	No
Emphasizes continuous improvement	Yes	No
Provides self-assessments	Yes	Yes
Applicable to projects	Software only	No
Applicable to programs	Software only	Yes
Applicable to organizations (operations)	Software only	Yes
Requires a quality management system	Yes	Yes

Conclusion:

CMM ensures that the process followed for developing a product produces error free product. A company which is process driven is more successful than the company which is people driven. Hence a company needs to have a good process for software development for it to be successful.