Effort estimation

The level of effort estimates given in Exhibit 4-1 are for time used by the project team. Design time is an estimate of the number of person days that will be needed to develop a fully defined system program/element or management process starting with the data collected during the assessment phase. 

The effort estimates are used to determine the amount of time each team member is expected to spend on the project, as well as the related cost of their services. The task-duration estimates, when combined with the project network diagram (see Figure 4), provide the basis for setting a project schedule (i.e., task start and completion dates). 

Early approaches to software effort estimation were based on this principle, a sophistication tending to be an adjustment by means of the application of exponentiation to take account of diseconomies of scale. These diseconomies can be caused by larger projects needing disproportionately more effort to deal with communication and management overheads. 

Accurate effort estimates can only proceed on the basis of good historical information and so the accurate recording of details of project cost and size is one of the indicators of a well-managed project environment. 

Koch, S., Mitlohner, J., 2010. Effort estimation for enterprise resource planning implementation projects using social choice a comparative study. Ent. Info. Sys. 4 (3), 265-281. 

Generally, only vague information is available at the beginning of a project and thus, as a first step, the project charter is formulated and defined. Frequently, specifications covering aspects of project planning and implementation are included. Moreover, problems and tasks are defined, targets of the project are recorded, and a description of the service to be rendered is created. These requirement specifications built the basis for the formulation of the project charter. Besides, a feasibility study, an effort estimation, a profitability analysis, and a risk analysis is covered in this starting phase. 

The feasibility study evaluates whether the resources required for the realization of the project such as qualified personnel, necessary technology, or financial resources are present and timely profitable. Within the scope of the effort estimation, the effort required for the execution of the project regarding its quantity and value is defined. The profitability anaiysis provides information about the expectable profit which is especially for internal projects of significance, as they include no contractual agreement concerning the revenue. Regarding the risk analysis, potential risks factors are identified which are obstructive for a proper project closure. In order to minimize the identified risks, suitable countermeasures are developed. 

However, due to the fact that SCD-Phase 4 of the guideline covers the selection and prioritization of corrective actions, certain decisions regarding the project conception phase of the implementation are already considered. The suggested analytical hierarchy process method to select corrective actions implies the consideration of criteria such as time, usability, risk, utility, and feasibility of implementation. Hence, the content of the project conception phase is already covered in this section and therefore, only the effort estimation, the profitability analysis, and the risk analysis are evaluated on a superficial level. 

The effort estimation constitutes the basis for the calculation of the project duration and its costs. A company determined whether the project is realizable, if resources are available within the time frame, and if the project is profitable. Thus, the decision is based on the quality and accuracy of the effort estimation. In order to be able conduct a usable effort estimation, experience and preparation are required. Generally, tree possible methods arise ... 

In order to be able to specify the further process of the project milestones should be defined. Milestones represent the process of the project in a rough manner with regard to its chronology. In order to be able to constantly verify the progress of the project, major projects are sub-divided into different phases with controllable intermediate results (Kuster et al. 2008). Thereby, the sub-divisions of the project may be built on the effort estimation evaluated in the project conception phase (Zimmermann et al. 2010). Regarding major projects or high insecurity within the project, it is advisable to define several milestones on critical points as depicted in Fig. 12.4. 

The computer subroutines for calculation of vapor-liquid equilibrium separations, including determination of bubble-point and dew-point temperatures and pressures, are described and listed in this Appendix. These are source routines written in American National Standard FORTRAN (FORTRAN IV), ANSI X3.9-1978, and, as such, should be compatible with most computer systems with FORTRAN IV compilers. Approximate storage requirements for these subroutines are given in Appendix J their execution times are strongly dependent on the separations being calculated but can be estimated (CDC 6400) from the times given for the thermodynamic subroutines they call (essentially all computation effort is in these thermodynamic subroutines). 

The number of injectors required may be estimated in a similar manner, but it is unlikely that the exploration and appraisal activities will have included injectivity tests, of say water injection into the water column of the reservoir. In this case, an estimate must be made of the injection potential, based on an assessment of reservoir quality in the water column, which may be reduced by the effects of compaction and diagenesis. Development plans based on water injection or natural aquifer drive often suffer from lack of data from the water bearing part of the reservoir, since appraisal activity to establish the reservoir properties in the water column is frequently overlooked. In the absence of any data, a range of assumptions of injectivity should be generated, to yield a range of number of wells required. If this range introduces large uncertainties into the development plan, then appraisal effort to reduce this uncertainty may be justified. 

As discussed in Sections 13.0 and 14.0, the management of operating expenditure (opex) is a major issue, since initial estimates of opex are often far exceeded in reality, and may threaten the profitability of a project. Within the FDP, it is therefore useful to specify the system which will be used to measure the opex. Without measuring opex, there is no chance of managing it. This will involve the joint effort of production operations, finance and accounting, and the development managers. 

Confederation of Independent States (CIS) are denoted as explored reserves and include proved, probable, and some possible gas. The data for Canada also include some probable reserves. The worldwide natural gas reserves have continued to increase as the demand for gas has increased and exploration efforts have expanded. In 1976, the world natural gas reserves were estimated to be 6.58 x 10. In 1987, the reserves were 1.06 x lO ", and by 1992... 

---