Construction Productivity Midterm

field-originated changes

"differing site conditions" where the physical condition on the site is either not what was expected or not apparent until construction progresses

crew balance chart

-a way of showing the interrelated activities of individual members of crews and their effects on the availability of the equipment they employ -the purpose of these charts is to achieve balanced resource usage. the primary rule is to record the activities of all crew members and equipment by observing the crew during a cycle of high cost and repetitive operations (i.e. pouring concrete or excavation)

what are disadvantages to shift work?

-additional management, supervisory, and support staff -problems caused by working at night such as lighting, heating, sleep schedule changes, disruption of personal lives -difficult coordination between shifts -keeping supervision over several shifts and transferring management information between shifts -not flexible in terms of adding short amounts of increased labor -added safety problems -not an option for many site conditions

assessments of craft labor availability usually address:

-available labor sources and demand in the area -area employment data -area wage data -per diem requirements -area accommodation and service info -similar work in the area -training needs -labor contingency recommendation

advantages of overstaffing/ trade stacking

-avoids fatigue problems associated with overtime -flexible option for acceleration

day of the week factors

-blue monday syndrome -cumulative fatigue at the end of the week -preference to not work on the weekends -less support/supervision on weekends -Saturday is sometimes a makeup day

list five reasons for turnover in the construction industry

-compensation -overtime available on another job site -work closer to home -inadequate tools and equipment -poor planning -poor overall management -mediocre supervision -unsatisfactory relationship with boss and colleagues -bad work environment; unsafe work environment

list four typical recruiting considerations used to attract skilled craft workers to a construction project

-competitive wage rates -per diem -completion (ROF) bonus -overtime -safety bonus -relocation assistance

advantages of extended overtime

-decreases overall schedule time -attracts workers because of increased pay

Rework Impact on Construction Cost

-direct costs caused by rework average 5% of total construction costs -$65 billion in rework annually (U.S.)

categories of sampling

-direct work -transport (supportive work) -travel (supportive work) -instruction (supportive work) -personal (delays) -idle (delays)

What are two reasons that productivity is worse in later phases of a project?

-higher craft density -congested worked areas due to already installed facilities -diminishing work fronts -punch-list work

list 3 primary approaches to improving construction labor productivity

-increase the % of time spent by craft workers on direct work -reduce the number of work hours required for one unit of work -reduce the amount of rework

What are typical reasons for underreporting rework?

-lack of rework reporting system -lack of training or discipline in cost code system -reluctance to self report mistakes

top 10 reasons for out of sequence work

-late design deliverables -change in design -expedited schedule to meet owner's requirements -schedule pressure -late vendor information -unrealistic activities duration -late delivery from vendors -poor communication between different projects parties throughout project -late scope changes requiring different/new equipment/processes -low clarity of scope while planning

advantages to sporadic overtime

-limited impact due to short duration -handles immediate problems quickly without future schedule changes -very flexible

list 5 demotivators under management control that you believe may have the most influence on labor productivity

-materials, tools, equipment are unavailable -poor relations between workers and management -poorly organized projects -breakdown in communications -lack of recognition of outstanding effort -disrespectful treatment -unfair work assignments -incomplete engineering/design work -lack of cooperation between crafts -poor supervision -rework -no participation in decision making process -restrictive and burdensome procedures

disadvantages of overstaffing/ trade stacking

-new workers to site have to be brought up to speed -can have productivity losses due to congestion

what are advantages to shift work?

-no immediate fatigue factors from overtime -no congestion factors from overstaffing or trade stacking -premium pay fo shift work is less than overtime pay -may be able to minimize cost of rental equipment -can give weather support if there are warm conditions during the day

sources of rework

-owner change -design error/omission -design change -vendor error/omission -vendor change -constructor error/omission -constructor change -transportation error

list five types of temporary facilities that should be planned and monitored by site management to ensure the facilities support labor productivity

-parking -orientation and safety training -lunch and break facilities -transportation and hygiene -trailers for supervision and support staff

List 3 reasons for absenteeism that may be attributed to management choices and actions

-poor overall management -poor supervision -excessive rework -unsafe working conditions -overtime

reasons for absenteeism overall

-poor overall management -poor supervision -excessive rework -unsafe working conditions -overtime -excessive travel distance to the job site -personal or family illness

disadvantages of extended overtime

-premium pay -loss in efficiency as hours per work week increase -requires increased management

disadvantages to sporadic overtime

-premium pay -requires increased management -fatigue causes productivity loss

five minute ratings

-quick appraisal of activity that is effective for making general work evaluations -can help management become aware of job delays and give a sense of their magnitude -can indicate or estimate a crew's effectiveness, and show more thorough and detailed observations or planning could result in savings -not statistically significant

Reasons to track rework

-recover cost associated with change -recover cost associated with error and omission by others -contractual requirement (incentives) -drive accountability internally -benchmark against industry -drive improvement efforts

List 5 ways that construction sites differ from manufacturing facilities that may explain some of the challenges in improving construction productivity compared to manufacturing

-short duration projects -on site work stations are not permanent -skilled workers are difficult to find -final product is of unique design -construction is a preliminary step leading to a completed facility, so the layout and arrangement may make access for construction difficult -operations are conducted outside- making the project subject to many factors such as weather -the owner is deeply involved in the construction process while the purchaser of manufactured goods is not -construction involves large scale, cumbersome, and heavy assemblies of vessels or other components that are difficult to handle and fasten in place

Name 3 jobsite conditions typically experienced in operating industrial plants that are commonly known to reduce labor productivity compared to greenfield sites

-space restrictions -permitting requirements -training for specific risks -scheduling challenges -expose workers to extreme temperatures

factors that magnify losses

-timing of the change -complexity of added work -the amount of time it takes to get the change formalized (processing time) -interdependencies among activities -intensity of the work and amount of room in schedule

identify 4 issues that should be considered when planning for small tools provided by the construction company on a project:

-tool room location -tool room checkout/in efficiency -quantity of tools -quality of tools -management of tool return for availability -management of tool theft

List the top four categories of factors affecting construction labor productivity in order of importance

1. tools and consumables 2. material 3. engineering/drawing management 4. construction equipment

How much of the US GDP does construction make up?

4.2%

What percentage of people work in construction?

4.9%, nearly 5%

average cost growth due to changes

5-10%

productivity ratio

=actual direct work hours/ estimated direct work hours

Labor Productivity

=direct work hours/ quantity installed

estimated direct work hours

=estimated labor productivity x total quantity

direct work rate

=observations of direct work/total number of observations

production rate

=quantity installed/time

T/F: If the owner of a project delays a construction contractor such that work planned to be performed during desirable weather time period must be performed during an undesirable weather time period, then they may be subject to a claim from the contractor for additional compensation due to productivity losses.

True

activity anaylsis

a continuous process of measuring and improving the amount of time craft workers spend on actual construction. This measured time is referred to as tool time, wrench time, or direct work time

define change relative to construction

any action, incidence, or condition that makes differences to an original plan or what the original plan is reasonably based on *not all changes become change orders

What is the implication of rapid growth in the construction industry?

availability of skilled craft workers and competition of skilled craft workers

list 7 concrete work activities that would typically be included in direct work hours

concrete placement installing reinforcing material loading material anchor bolt installation finishing concrete fabrication of forms hauling and unloading field installation of all embeds

work sampling

consists of observing and classifying a small percentage of a project's labor activity

early phase productivity

early phases often have low productivity when the flow of resources are still being established and craft workers are hired early

Describe one construction activity commonly used to mitigate productivity losses due to adverse weather conditions that impact civil construction work in the field

laborers: set up rest tents site: mud slab (wet), lime treatment (wet)

later phase productivity

later phases tend to have lower productivity due to higher craft density, more congestion from already installed facilities, diminishing work fronts, and punchlist work

bulk material

material ending up in the final product

consumables

materials that dont end up in the final product; materials you dont see or get back

what are the 3 types of acceleration

overtime shift work overstaffing/trade stacking

premature mobilization

premature mobilization to the field before engineering is sufficiently complete to support efficient work schedules may lead to rework and inefficiencies

day of the week productivity

productivity is best on tues/wed/thur worst on saturday and sunday

define production

rate of installation in the construction process measured as a ratio of output to a period of time

define productivity

relative efficiency of labor utilization in the construction process measured as a ratio of input to output

foreman delay surveys

reports by foreman about causes of delays of their crews. By measuring delays that are beyond the control of the foreman, the survey acts as a measure of management's effectiveness at planning work, allocating tools & equipment, and materials

Direct Work

the act of exerting physical effort directed towards an activity, or physically assisting in these activities that actually build or complete the installation or project; also known as tool time or wrench time.

define acceleration in context of construction

the addition of labor hours per week to complete work faster than originally planned. This can be allowed to get a project back on track after delay or when the owner wants an earlier project completion date.

How might the project delivery method for heavy industrial projects make them more likely to suffer significant productivity losses than infrastructure projects?

the significant engineering, procurement, and construction phase overlap for heavy industrial projects, leading to late engineering, material, and equipment deliveries-- resulting in productivity losses

T/F: project construction activities during phases later in the project time period tend to have lower productivity than experienced in the middle of the project.

true

middle phase productivity

typically the most productive phase

craftsman questionnaire

used to canvas the craft on problems with availability of materials, tools, equipment, scaffolding, etc. These surveys also isolate issues relating to rework, crew interference, job instructions, and working conditions. helps management identify inefficiencies that may be improved on

is it possible to have both worse than planned labor productivity and better than planned production rate?

yes