Presentation on theme: "Ch-5 Process Database and Process Capability Baseline."— Presentation transcript:
Ch-5 Process Database and Process Capability Baseline
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.
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
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
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: 1. Project planning:- past data from completed projects are invaluable in developing reasonable plans for a new project 2. 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 3. 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.
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
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: 1. To aid a new project in planning, particularly in the estimation of effort and defects 2. To collect quality and productivity data on different types of projects 3. To aid in creating process capability baseline 4. To facilitate data analysis for identifying areas and scope of improvement 5. The data on reviews are not kept in this database but maintained separately
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: 1. Project characteristics 2. Project schedule 3. Project effort 4. Size 5. Defects