Staffing level estimation

About staffing level estimation

1. Software Engineering Staffing Level Estimation Submitted by, M. Kavitha, II – M.Sc (CS&IT), Nadar Saraswathi College of Arts & Science, Theni.

2. Staffing level estimation : * The number of personnel required throughout a software development project is not constant. * Planning and analysis are performed by a small group of people, architectural design by a large, but still group and details design a large number of people. * Implementation and system testing require the largest number of people. * Maintenance may require numerous personnel but the number should decrease in a short time.

3. * In 1958, Norden research and development project. Cycles : A. Planning B. Design C. Prototype D. Product E. Modification

4. * A cycle of planning, design, prototype, development and use with the corresponding personnel. * Any particular point on the Rayleigh curve represents the number of full-time equivalent personnel at that instants in time (NOR58). * The Rayleigh curve is specified by two parameters, td the time at which the curve its maximum value. * Then K the total area under the curve which represents the total effort required for the project.

5. E = K / t 2 d t e – t2/2t2 d Fig 2 : The Rayleigh curve of effort vs. time

6. In 1976, Putnum reported that the personnel level of effort required throughout the life cycle. Fig 3 : Putnum’s interpretation of Rayleigh curve(PUT76)

7. A. Design and coding (15%) B. Test and validation (20 %) C. Extension (10%) D. Modification (25%) E. Maintenance (20%) F. Management (10%) * The planning requirements analysis and functional design in the project curve. * Boehm the Rayleigh is reasonably accurate estimator of personnel development cycle. * The development cycle from architectural design through implementation and system testing if the portion of the curve between 0.3td and 1.7td.

8. Where , PM - estimated number of programmer months for product development (excluding planning and analysis) TDEV - estimated development time. FSP – Full – time Software personnel.

9. * FSP required at any particular time t, where t is in the range 0.3td to 1.7td. * Then td is still the time of peak staff requirements but it is no longer interpreted as the elapsed development time. * The plot of the personnel requirement as a function of time for a 32-KDSI, 91-PM. COCOMO Rayleigh Design System test FSP t, months

10. Activity Effort Schedule 32 KDSI 128 KDSI 32 KDSI 128 KDSI Plans and requirements 6% 6% 12% 13% Architectural design 16% 16% 19% 19% Detailed design 24% 24% Combined value : Coding and unit test 38% 36% 55% 51% System test 22% 25% 26% 30% Table 1 : Distribution of effort for application programs

11. Activity Effort Schedule Personnel 32 KDSI 128 KDSI 32 KDSI 128 KDSI 32 KDSI 128 KDSI Plans and requirements 5PM 24PM 1.2MO 3.1MO 2.9FSP 8 FSP Architectural design 15PM 63MM 2.2MO 4.6MO 5.6FSP 14FSP Detailed design 22PM 90MM Combined Values : Implementation 34PM 141MM 7.7MO 12.2MO 7.3FSP 19FSP System test 20OM 90MM 7.2MO 7.2MO 5.6FSP 14FSP Table 2 : Distribution of effort, schedule and personnel

12. * Boehm also presents tables that specify the of effort and schedule in a software development project. * The total number of programmer months and total development time can be used estimate the actual number of programmer months and elapsed time for each activity. * An estimate of the number of full time software personnel required in each phase of software development and divided number of programmer month.

13. Thank You