1. Process Database and Process Capability Baseline
Ch-5
Process Database and Process Capability Baseline

2. Introduction
In any organization past experience plays an important role in improvement and management
Past experience can be used for improvement and process management
For software projects, process database (PDB) and process capability baseline (PCB) are two mechanisms for encapsulating past experience for use in project planning and management
PDB and PCB encapsulate the experience with previous projects, mostly in form of software metrics data and make it available to fresh projects
Information from PDB and PCB is used during project planning
These two mechanisms are not the part of planning phase. They provide the key inputs for planning.
The main source of data for these two components is the completed projects.

3. Continue…
The data collected in the projects is analyzed and then reported in closure reports which forms the main source for the PDB.
The data in PDB are then used to compute the PCB
Process database is required at CMM level 3.
At level 3 the database is largely used for collecting assets and experience from different projects
At level 4 PDB is likely to be used for performing process analysis computing the process capability and quantitatively controlling the project

4. Software Metrics and Process Management
Software metrics can be used to quantitatively characterize different aspects of the software process or software products.
Process metrics quantify attributes of the software process whereas product metrics are measures for the software products
Eg of process metrics include productivity, quality, resource metrics defect injection rate, defect and removal efficiency
Eg of product metrics include size, reliability, quality

5. Purpose of Collecting Metrics Data
For any metrics program we must clearly understand the reasons for collecting data as well as the models that will be used for making judgments based on the data.
Important uses of metrics in a software organization are as follows:
Project planning:- past data from completed projects are invaluable in developing reasonable plans for a new project
Controlling a project’s process:- metrics can provide accurate information about the state of a project which can then be used to take corrective actions in a timely manner
Analyzing and improving the organization’s process:- through metrics organization can know the quality and productivity capability of its process and the change in quality and productivity with time.

6. Metrics and Statistical Process Control
Statistical process control is a technique that is used in manufacturing
The purpose of SPC is to control the process of production so as to reduce the variability in the values of the output’s quality characteristics to improve the quality
Number of factors affect the characteristics of the process output
These factors can be classified in to two categories: natural or inherent and assignable
A process is said to be under statistical control if the variability in the quality characteristics is due to natural cause only.
For applying SPC, control charts are favorite tool.
In control chart, output of a process is considered as a stream of numeric values, representing the values of the characteristics.
Control charts are used to continuously monitor the performance of the process and identify the out- of- control situation

7. Process database
Process database is a permanent repository of process performance data from projects which can be used for planning, estimation, analysis of productivity and quality, and other
PDB consists of data from completed projects
So to populate PDB data must be collected in projects, analyzed, and then organized for entry into PDB.
The key purposes of PDB are:
To aid a new project in planning, particularly in the estimation of effort and defects
To collect quality and productivity data on different types of projects
To aid in creating process capability baseline
To facilitate data analysis for identifying areas and scope of improvement
The data on reviews are not kept in this database but maintained separately

8. Contents
It should contain all data about projects that may be useful for projects in planning and estimation as it aids in project planning and estimation activities
The data about a project can be classified according to the categories:
Project characteristics
Project schedule
Project effort
Size
Defects

9. Data Entry and Access