COCOMO II adds three more formulas to adjust estimates for 1 developing

• 517

This preview shows page 287 - 289 out of 517 pages.

COCOMO II adds three more formulas to adjust estimates for 1) developing prototypes, 2) accounting for the amount of code reuse, and 3) a post-detailed-architecture estimate. This last formula expands Size Penalty by adding a normalized product of 5 independent factors and replaces Product Factors by a product of 17 independent factors. The British Computer Society Survey of more than 1000 projects mentioned in Chapter 1 found that 92% of project managers made their estimates using experience instead of formulas ( Taylor 2000 ). As no more than 20% to 30% of projects are meet their budget and schedule, what happens to the rest? Another 20% to 30% of the projects are indeed cancelled or abandoned, but the remaining 40% to 50% are still valuable to the customer even if late. Customers and providers typically then negotiate a new contract to deliver the product with a limited set of missing features by a near-term date. ELABORATION: Function points Function points are an alternative measure to LOC that can lead to estimates that are more accurate. They are based on the function inputs, outputs, external queries, input files, output files, and the complexity of each. The corresponding productivity measure is then function points per person-month. PERT stands for Program Evaluation and Review Technique, which was invented by the US Navy in the 1950s for its nuclear submarine program. 4. Scheduling and Monitoring Progress. Given the SRS has been broken into tasks whose effort has been estimated, the next step is to use a scheduling tool that shows which tasks can be performed in parallel and which have dependencies so they must be performed sequentially. The format is typically a box and arrow diagram such as a PERT chart . Figure 7.14 gives an example. Such tools can identify the critical path , which determines the minimum time for project. The project manager that places the graph in a table with rows associated with the people on the project, and then assigns people to tasks.
Figure 7.14: Numbered nodes represent milestones and labeled lines represent tasks, with arrowheads representing dependencies. Diverging lines from a node represent concurrent tasks. The numbers on the other side of lines represent the time allocated for the task. Dotted lines indicate dependencies that need no resources, so they have no time allocated for the task. Once again, this process is typically done twice, once when bidding the contract, and once after the contract is won and the detailed architecture design is complete. Safety margins are again used to ensure that the first schedule, which is when the customer expects the product to be released, is not longer than the second version. Similar to calculating velocity, the project manager can see if the project is behind by comparing the predicted expenditures and time for tasks to the actual expenditures and progress to date. A way to make project status clear to all stakeholders is to add intermediate milestones to the schedule, which lets everyone see if the project is on schedule and on budget.

#### You've reached the end of your free preview.

Want to read all 517 pages?

• Spring '19
• Dr.Marcos

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern