Value-based software engineering a case study

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Computer Science, Engineering. Charting your company's future. Our conclusion is that we need to change our methods for search-based software engineering, particularly when studying complex decision spaces. Documents: Advanced Search Include Citations. Plan for co-ordinating with designer to obtain agreeable basis of costs. VE Workshop. Location and day-by-day agenda for workshop. Plan for availability of design staff to answer questions. Post Workshop Procedures.

Schedule for oral presentation. Schedule for preparation and submittal of prelim- inary VE report. Schedule for preparation and submittal of final VE report. The estimated level of effort for the design firm should be shown separately. Technical Areas to be Investigated - Unit process design cri- teria, structures, electrical, mechanical, plant layout, site.

VETC: Co-ordinate with the designer"arid validate basis of cost estimates; distribute material from designer to team members; arrange facilities for workshop. Workshop Show agenda for each day : L. Describe timing and scope of VE study. Describe team responsibilities. Estimate by designer of project costs capital and operation and maintenance presented separately. Estimated project costs after VE capital and operation and maintenance presented separately.

Brief Narrative Description and schematic sketches of before vs. Estimated Implementation Costs. Documentation for VE Recommendations. Validation of Designer's Original Cost Estimates. Documentation Related to Each Recommended Change. Description of Recommended Change. Before and After Design Criteria. Cost' Models 2. Functional Analysis 3. Speculative Phase 4. FAST Diagrams 5. Idea Evaluation 6. Cost Analysis 7. Alternative Evaluation 8. Tabulate Accepted Recommendations. Schedule and Related Costs.

The following specific recommendations should be carefully reviewed prior to preparation of the VE report: - Make each VE recommendation brief, clear and complete. Each recommendation should be supported by: Before and after design criteria. Before and after sketches. Before and after costs. Information on how costs were developed i. A list of other alternatives relating to the recommendations, which were seriously considered, the reasons for their rejection.

Before and after sketches are very helpful and should be included. These should be clear and should be as detailed as necessary to explain the proposal.

They should not however, include unneces- sary detail, accuracy or embellishment. Portions or reduced portions of construction drawings are not usually effective. It should be divided into four proposals with each expanded to explain quantitatively what is really being proposed and why. Government, PL , how designers design, etc.

The report is for the designer and the owner's technical staff along with the fund- ing agencies to review and evaluate. Functional analyses, FAST diagrams, cost models, weighting and evaluation sheets , brainstorming lists , etc. Be explicit about the acceptance of rejection of recommendations without saying, for instance: "This recommendation was referred to the electrical engineering department for further analysis". Accept the recommendation or'state why it is rejected.

Be consistent in numbering the VE ideas so they can be readily traced from the VE workbooks through the summary portions of the final report. A simple system such as "F-3" to indicate the third idea of the foundation F. This latter point will become less of variable under the man- datory program because projects will plan for VE prior to the initiation of Step 2.

As a project progresses through Step 2, the potential for savings through VE decreases because the cost of implementing changes be- comes greater. The level of VE efforts for studies later than this in Step 2 should be reduced to reflect the reduced potential for re- turn. The major elements to be determined for a given VE study are: Total manpower required and number of workshops.

Number and composition of the VE team s. For example,: a large advanced waste treatment pro- ject may readily justify separate teams, each with a study area such as structures, mechanical, electrical, process, and site. If the system in question is simply an add-on to an existing plant to provide a single pro- cess, the level of effort may be relatively small and readily handled in one VE review.

On the other hand, a small but highly refined-system, to provide the ultimate that today's technology can achieve, would require above average effort. Typically, one VE team consists of five members.

In some cases, larger teams may be justified and have been used on particularly large and complex projects. However, for most projects, the five man team will be an appro- priate size. Conducts the Project Review Workshop. Prepares the Preliminary VE Report. Participates in implementation Phase - as required. The designer's participa- ' tion is passive and any defensive reactions must not be allowed to interfere with the generation of alternative ideas.

Table 1 presents typical levels of effort associated with varying numbers of VE teams fojr one or two workshops. There may be cases where the first of two workshops utilizes more teams than the second. For example, one five team workshop followed by a later three team workshop would result in an estimated level 0f effort of Thus, greater VE effort is usually made at this point than at the time of the second workshop. There may be unusual cases where in- creases over the estimates in Table 1 are clearly justified but drastically greater proposed efforts may indicate that work which should be done as part of the design effort cost estimation or analysis of alternatives out- side of constraints for example is creeping into the VE effort.

The designer's estimated supporting level of effort should be considered as a budget guide only with actual payment based on cost-plus- fixed-fee. The effort actually required of. Redesign effort to implement VE recommendations is not part of the VE effort.

The appropriate overall level of effort is chiefly a function of plant size"'and complexity. Complexity is difficult to quantify. For example, secondary treatment plant complexity itself can vary substantially as a function, for example, of the sludge disposal process land application of digested sludge is much less mechanically complex than mechanical thicken- ing, dewatering, and incineration.

Perhaps the best indicator of potential complexity and the potential for savings from VE is the cost of a given capacity plant. Based upon a cost analysis of several plants of varying capacity and complexity and an estimation of VE effort for each, a nomograph Figure 1.

A straight line is drawn from the plant capacity being constructed the capacity being added in the case of a plant expan- sion through the estimated construction cost. The point at which the extension of this line strikes the right axis of the nomograph provides an estimate of the appro- priate level of the VE effort.

For example, a plant abandoning land disposal of sludge for a system utilizing mechanical dewatering and incineration might have no associated change in treatment capacity Such cases will usually involve a limited number of sub-systems and the guidelines in the EPA VE Workbook for projects of limited complexity page 12 may be used for guidance.

With the limited number of sub-systems involved for example, no extensive site considerations involved because it is an addition to an existing facility , such a level of VE effort appears appropriate.

For example, VE of a major land treatment system should involve personnel with agricultural engineer- ing, irrigation system design, and perhaps farm management skills. These skills would be totally inappropriate for a conventional secondary treat- ment plant project.

Regardless of the specific technical skills required for a project, there are some universally applicable considerations for team members. Team members should be highly qualified in the disciplines they repre- sent. The competence of the individuals who make up the VE team s is probably more important than the precise composition of the teams.

Hav- ing too many members from the same discipline on a team may stifle creativ- ity. The participants proposed for the study should have current design, construction, procurement, operation or administrative experience suited to the analysis of the subject design. The importance of the preceding sen- tences cannot be overemphasized. One team of highly competent, creative individuals may recommend and identify many times the VE savings of several teams of mediocre personnel.

As noted in the VE Workbook the goals of VE "can only be achieved by all parties working together in a harmonious and constructive atmosphere". When an outside firm or personnel are used for VE, the VETC and team members should be selected with the advice of the Owner's design firm, but should perform the VE study independently. Seeking the advice of the de- signer will insure that the designer respects the technical ability and integrity of the VE teams and establishes the basis for the co-operative atmosphere needed for a successful VE study.

As noted earlier, a typical VE team consists of five members. Where multiple teams are used, it is desirable that each team has a designated leader who has had VE workshop training and experience as well as the needed technical expertise.

It is difficult to generalize on skills needed i. In all cases, some of the skills may be drawn with beneficial results from the Owner's staff if the needed skills may be found there and are available. Changes in the process selected in Step 1 are normally out- side the scope of a Step 2 VE study because of the potential for delays by reopening Environmental Assessment procedures, etc.

Thus, team emphasis on sanitary process is usually not provided. Personnel with actual waste- water plant operation and maintenance experience - whether they be electri- cal, mechanical, civil, in education - should be included when appropriate. Team members with background in construction may also provide a useful perspective. Some individuals may offer expertise in more than one area i. For some processes - particularly AWT processes - chemical engineering skills might well be utilized on some teams.

Emphasis in team orientation must reflect local conditions. If, for example, foun- dation conditions are very straight forward with little potential for savings, this team might be replaced by one solely oriented toward pumping and piping.

An alternative to structuring the teams on a discipline basis i. Each team would then have a broad range of disciplines electrical, mechanical, civil, structural, sanitary, etc.

These case studies were made to supplement, with actual field experiences, the VE Workbook MCD on application of VE techniques to wastewater projects. In order to collect information on the projects, meetings were held with the designer, value engineer, owner, state regula- tory agency, and in some cases, Regional EPA personnel on each project.

In most cases, each of the parties involved in a given project were inter- viewed separately in order to obtain their individual views on the VE study. The study of each project is presented separately. The goal of each project was to develop the following information: 1. VE recommendations; 5. Reason and analysis for each rejection; 7. VE fees and implementation costs; 8. Separate sections present specific guidai ;e on level of VE effort and on recommended formats for VE proposals and reports.

It should be kept in mind that most VE efforts under the EPA voluntary program were made under less-than-optimum conditions.

Frequently, the decision to include VE came late in the design effort. Description of the Proposed Project Prior to VE Study The original Lebanon wastewater treatment plant trickling filter pro- cess was placed in operation in with the addition of a Secondary clarifier in The facility performed satisfactorily. More stringent effluent stand- ards. A study. The original plant consisted of the following unit processes: 1.

Influent Pumping 2. Headworks Comminutor and aerated grit chamber 3. Measurement 4. Primary Clarification'" ,. Secondary Clarifier " , 7. Anaerobic Sludge Digestion 9. Sludge Drying. The originally proposed plant expansion included the construction of a new plant pump station with a capacity sufficient to allow all storm flow to receive treatment before it is discharged.

This pumping capacity eliminated all bypasses and allowed the abandonment of an existing storm- water pump station. The abandonment of the pump station required the construction of a new inch sewerline parallel to an existing inch sewer to the treatment plant.

The space occupied by these facilities was used to provide storage for chlorine and miscellaneous plant equipment and supplies. The new plant pump station would pump the raw sewage to a new headworks consisting of a flow division box,comminutor, and hydrasieve screen. The flow division box allowed a flow of up to 8 mgd to pass through the commin- utor and on through the rest of the plant. Storm flows in excess of 8 mgd were split to a hydrasieve screen where the sewage receives the equivalent of primary treatment after which it flows by gravity to a chlorine contact chamber for disinfection prior to discharge.

The comminuted effluent would flow by gravity to the aeration basin. The aeration basin consisted of two cells for flexibility of operation with each cell utilizing three hp mechanical aerators to aerate and mix the contents of the basin.

The aeration basin effluent would flow by gravity to the existing primary and secondary clarifiers. The existing primary clarifier would be modified so it can serve as a secondary clarifier. A secondary effluent pump station pumped secondary effluent to the mixed media filtration complex. The filters are required to meet the more stringent effluent standards. The filtered effluent would flow by gravity to a chlorine contact chamber where it would be disinfected before dis- charge.

The existing chlorination facilities would be expanded. Other proposed additions to the plant included a new aerobic digester, new sludge drying beds, and conversion of the existing anaerobic digester into a storage facility for aerobically digested sludge. The existing trickling filter was to be removed. The existing sludge drying beds were to be relocated to allow for a more economical layout of the expanded plant. In addition to the drying beds, a liquid sludge loading dock would be provided near the sludge drying beds to enable flexibility for truck haul of liquid digested sludge to farmlands as a fertilizer.

A dried sludge storage building would be provided to allow stockpiling of dried sludge. It was assumed that the ultimate disposal of the digested waste solids would be on local farmland as a fertilizer - a successful, established practice at Lebanon. Costs are discussed in more detail later in this report. One VE team included an engineer from outside the design firm. Team 1, called the "over- view team," began its study. Team l's main area of concentration was major design concepts, facilities plans, and processes.

Some ideas were remanded :from Team 1 to two succeeding VE teams. Team 2 called the "architectural - structural team" and Team 3 called the "mechanical, electrical, instrumentation and control team", made subsequent studies at the 25 percent design stage. Civil Engr. Senior engineers from the design firm comprised this review team.

The function of the review team was to compare the original design as conceived by the design team, with the alternative design as conceived by the value engineering teams. If a VE team proposal was accepted by the review team, the design team was instructed to incorporate the modi-: fication into the design. If a VE team proposal was rejected by the review team, a full explanation was given for the rejection. Architect " One of the four sanitary engineers on the review team was also the" project design engineer.

Teams 2 and 3 each met for hour sessions and gener- ated some new ideas as well as evaluating in detail several ideas proposed by"Team 1. The VE study was conducted as a lump sum amend- ment to an existing contract between the City and the design firm for the design of the Lebanon plant. The initiative for the VE study came from the designer who made a presentation to the City Council on the merits of VE. The following advantages of an in-house VE team as compared to an outside VE team were presented.

With an in-house VE team, the designers know the qualifications and motives of the VE team members whereas with an outside firm doing the study, qualifications, motives, and attitudes of the parti- cipants are unknown.

He feels that the one preliminary VE team early in the design followed by two VE teams represents a minimum level of effort in this cost and complexity range.

The VETC has experimented with team workshop periods greater than 40 hours and has concluded that the benefits gained are not proportional to the added cost. The review team and cost estimator used in the Lebanon study performed outside the 40 hour limitation but the 3 VE teams accomplished their work within 40 hour periods 24 hours for VE Team 1.

A key element in the VE work was having design team cost estimates available for VE teams 2 and 3 so that VE teams did not have to develop cost estimates for the proposed design. VE Study Summary At the beginning of the information phase, the Overview VE team gathered all of the available design documents, including a conceptual cost estimate shown in Table 2.

Say Secondary System,. A cost model Figure 5 was then developed" to identify those functions that have a, poor cost-to-worth ratio. The worth.. The worth values shown in Figure 5. Each of the three VE teams then entered the speculative phase. There were no constraints placed on the scope of ideas. The ideas generated were then ranked during the analytical phase on a scale from 1 to 10 10 being the top of the scale for the ideas judged to be of most potential.

If any member of the VE team felt an idea was worth pursuing, it was given a ranking of 5 or more. The design firm now uses a "fail-or-pass" system rather than attempting any numerical , rankings at this stage.

Documentation of. In areas where the design hadn't. In some cases, major assumptions had to be made to perform the economic analyses. These assumptions were rioted in the VE; report.

The review team then compared this new alternative to the original design and decided which of the two designs was to be used. Table -4 presents the VE ideas which were accepted by the design team. Costs to implement the VE changes were not defined but were considered "minimal" because there was little impact on already completed design work. No delays resulted. The DEQ accepted the proposed changes although they did request automated freeze protection for any outdoor pumps.

Figure 3 presents the post VE layout of the plant. The raising of the con- tact chamber requires. The VE report does not quantify these added costs. The DEQ was also concerned that all the costs associated with relocation of piping and the distribution box to permit relocation of the chlorine contact chamber may not have been fully recognized. The DEQ also raised some questions at the time of the VE report about the justification for the added capital costs for the restart unit for auto- matic restart of motors following a power bump.

A review of the project final plans and specifications was made to determine how the items in Table 4 were incorporated. The specifications still provided for the original mixed media filters with the dual-media option being noted in the specifications as an acceptable alternate if the supplier provides satisfactory performance data to the engineer.

Any rede- sign required for the alternative filter systems was specified to be the responsibility of the supplier. The other major VE items were incorporated essentially as suggested by the VE teams. The DEO reported that the Step 3 grant application for the Lebanon pro- ject showed a slightly higher project cost than the pre-VE estimates which had been made on a March, basis.

The DEQ recognized that the final estimate was a more detailed estimate and that inflationary influences were now real rather than projected. However, they were concerned about how one can effectively evaluate the savings actually resulting from VE under these conditions. General Observations The design team personnel felt the VE process offered a welcome review and that the VE review will make for a better effort on the next design. The design personnel appear to have an increased awareness of costs in the early design phases knowing that a VE effort will be made.

The design firm now incorporates the VE efforts as project milestones in the basic project workplans to insure that all needed data are available to the VE teams. Process and instrumentation drawings have been found to be an especially important item for the VE study. The designer feels that in-house VE studies have merits which should be carefully considered.

Inclusion of some VE team members from outside the design firm helps ,to insure the client that objectivity is maintained. The basic client reaction expressed by the City Engineer was favor- able to the VE study. He felt that the. He felt the timing of the VE study was excellent and that there were no implementation problems associated with the VE suggestions'. He felt that the original process selection study had been well performed and that discussion of other alternative processes were not justified.

He thought the balance of the disciplines and involvement of outside personnel on the overview team VE Team 1 was very good. He felt the VE study was an excellent opportunity for the City personnel to learn in detail how the new facility will operate and that there is probably no other way that would be comparable in effectiveness in this regard. The VE Team Coordinator had to spend some time convincing the. A field trip by the team members, to the plant under study would be worth- while.

The City Engineer felt the design personnel were helped signifi- cantly by the VE study and that the help was gratefully received. The DEQ personnel believed that more regulatory agency input and in- volvement should be provided on the next VE project. They felt the perspec- tive they have from review of all projects in the State would be useful in the VE study. They also felt that addition of personnel with construction experience to VE teams would be worthwhile. The ,VE report should clearly spell out any risks associated with the VE re commendations,.

Lime is added to the primary clarifiers to provide removal of heavy metals.