تبلیغات
RF2268AM - CONSTRUCTION PRODUCTIVITY MEASUREMENT: A COMPARISON OF TWO CASE STUDIES 3
دوشنبه 29 فروردین 1390

CONSTRUCTION PRODUCTIVITY MEASUREMENT: A COMPARISON OF TWO CASE STUDIES 3

   نوشته شده توسط: عارف محمدی    نوع مطلب :مدیریت منابع سازمانی ،

To overcome the problems discussed in the previous section regarding the isolation of construction activities in measuring productivity, a decision was made to measure productivity levels using the existing company worker timesheets. Timesheets were found to be extremely useful mainly because timesheets were used for the purpose of calculation of hourly wages and linking this to productivity measurement would probably show meaningfully the notion of a fair wage. Furthermore, measuring productivity on a daily basis was considered to be the most appropriate technique as corrective action could be taken as quickly as possible. For data collection purposes, foremen were instructed to complete time inputs and physical outputs for each worker under their charge within a set time sheet on a daily basis. Table 1 below shows a simplified example of a recording on the activity of pouring concrete by a gang of concrete labourers. Based on the data presented in table 1, a total of 66 man-hours were used to produce 232m3 of concrete, yielding a productivity rate of » 3.5m3 of concrete per man-hour.

 

Date

Worker

Activity

Hours

Location/Output

1 Oct 2001

Foreman A

Pouring Concrete

10

Plot 2-6/ 232m3

1 Oct 2001

B, C, D, E, F, G, H

Pouring Concrete

8 each

Plot 2-6/ 232m3

Table 1: A simplified example of a completed time sheet

 

Emerging issues

A number of issues arose whilst attempting to measure on-site productivity levels for project A in this way. The desire for a speedy construction process meant that many proprietary systems, e.g. in the case of formwork, were used as part of the construction techniques. These were undertaken by specialist subcontractors (with whom access was not granted). What was observed was that the core labourers used by the main contractor were general operatives who were often mobile in terms of the task they did. So, for example, an operative could be involved in general housekeeping on day n, shifting what is known as ‘tables’ (a proprietary form of the conventional birdcage scaffolding that is on wheels to support the formwork) on day n + 1, and putting stop ends along the perimeter of a plot prior to concreting to prevent the concrete from spilling over on day n +2 and so on. Perhaps the only stable groups of workers were those who were relatively more skilled, e.g. concretors and steelfixers, who tended to stick within the task of their trades. Even so, these workers moved to other projects in the vicinity when their tasks were not scheduled for project A. Therefore, while measuring productivity levels in this way appear to be more holistic and probably closer to reality than the methods highlighted in the previous section, the mammoth task of tracking workers posed an immense challenge. Moreover, although the data was collected at the gang level (through the foremen), the boundaries of the gang were found to be arbitrary because of the volatile movement of the workers. This resulted in high variability of the productivity data obtained, which supports Radosavljevic’s and Horner’s (2002) observations, but which implies that discerning the factors affecting productivity especially those related to the workforce issues was particularly problematic.

Administering the measurement was also not without problems. To start with, foremen were not akin to filling out forms and throughout its implementation, the project quantity surveyor discovered that there was a need to constantly explain to the foremen the mechanisms of recording. Two reasons accounted for this. The first relates to the inevitable problem with determining output quantities given that construction operations are often associated with work-in-progress that can be difficult to ascertain. Rules of credit (see e.g. Thomas and Yiakoumis, 1987) may go some way to facilitate this process, although time and manpower is needed to maintain a database of such information for which the project quantity surveyor did not have. In fact, the project quantity surveyor resigned in the middle of the project and the measurement of productivity halted due to the absence of a willing successor. To exacerbate the problems of measurement, the project quantity surveyor had identified a complex list of more than 170 task descriptions, thus causing further confusion for the foremen in the recording process. This enormous list of task descriptions is believed to be due to the fact that many proprietary systems were used in the construction process. Still, as the predicted trend for the construction industry is towards greater outsourcing and use of innovative technology in the production of buildings (see e.g. CRISP, 2001), it would be sensible to take into account such complexities when measuring productivity. It is here that project B sheds some light.

 

Project B: Headquarters of a Commercial Bank

 

Background to project B

Project B involves the construction of the headquarters of a commercial bank on a greenfield site just outside Edinburgh. Access was given to interview senior project managers and to conduct questionnaire surveys with the site operatives. During the interviews, the researchers were struck by the ability of the managers to report what they allege to be the precise number of man-hours expended on the project to date, a phenomenon that was non-existent in other projects observed during the study. Inquisitively, the researchers investigated how project participants captured this data through further probing during the interviews.

 

Figure 1: Extract of project B work package 1 planning and progress update up to week 41

 

According to the project managers, project B utilised what is known as The Last Planner system, a planning system that has gradually gained recognition and refinement since its inception in 1994. Much has been written about the system (see e.g. Ballard, 2000), although this is really related to planning and never intended to be used as a means of measuring on-site productivity. However, one of the KPIs resulting from this system, known as the Percent Plan Complete (PPC), was thought to be extremely valuable by the project participants for them to gain an informed view of the on-site productivity levels. Basically, the PPC refers to how much of the planned work on a weekly basis is actually completed. In a similar vein, this ostensibly is comparable to the earned value analysis used in project management (see Project Management Institute, 2000). Figure 1 above shows an extract from a weekly progress update, which enables project B’s participants to keep track of how productively the work packages were performing to plan. To help improve the PPC, the progress meetings were used as a platform to understand what went wrong, i.e. what intervening events or factors resulted in a low PPC (e.g. weather, lack of materials etc.).


http://paibama.strikingly.com/
دوشنبه 3 تیر 1398 03:03 ق.ظ

Terrific data, Appreciate it!
generic cialis 20mg tablets dosagem ideal cialis the best site cialis tablets cialis manufacturer coupon cialis 200 dollar savings card generico cialis mexico 5 mg cialis coupon printable cialis from canada cialis herbs effetti del cialis
Buy cialis online
یکشنبه 2 تیر 1398 11:09 ق.ظ

Regards. A good amount of stuff.

side effects of cialis cialis generique comprar cialis navarr cialis generic tadalafil buy cialis for sale south africa cialis tadalafil warnings for cialis cialis kaufen price cialis best cialis generico postepay
Cialis canada
شنبه 1 تیر 1398 08:30 ب.ظ

You mentioned this well.
get cheap cialis we like it safe cheap cialis tadalafil generic cialis price thailand buy original cialis generic cialis review uk dose size of cialis achat cialis en suisse cialis para que sirve cialis generico lilly
http://siepiesan.strikingly.com/
شنبه 1 تیر 1398 03:33 ق.ظ

Awesome stuff. Cheers.
cialis online deutschland cialis super kamagra cialis kaufen cialis daily new zealand cialis canada on line cialis generico lilly cialis generico online cialis per paypa cialis purchasing cialis coupons
Cialis pills
جمعه 31 خرداد 1398 11:32 ق.ظ

Fantastic forum posts. Cheers.
cialis prices cialis generika female cialis no prescription cialis online napol cialis 10 doctissimo tadalafil 20 mg generic cialis tadalafil cialis without a doctor's prescription cialis for sale acheter cialis meilleur pri
cialis 20mg directions
پنجشنبه 30 خرداد 1398 06:58 ب.ظ

Truly many of beneficial tips!
if a woman takes a mans cialis tadalafil 20 mg purchasing cialis on the internet cialis en mexico precio cialis prezzo in linea basso cialis australia org 40 mg cialis what if i take cialis rckenschmerzen cialis kaufen cialis generico en mexico
http://negoldwen.strikingly.com/
پنجشنبه 30 خرداد 1398 12:36 ق.ظ

You explained this superbly.
cialis ahumada generic cialis best generic drugs cialis cialis daily dose generic fast cialis online buy cialis sample pack cialis sale online callus generic cialis soft gels cialis sans ordonnance
http://ersunre.strikingly.com/
چهارشنبه 29 خرداد 1398 07:54 ق.ظ

Wonderful forum posts. Cheers!
generic for cialis cialis super acti tadalafil 20 mg cialis dose 30mg generic for cialis opinioni cialis generico cialis daily new zealand low dose cialis blood pressure cialis reviews generic cialis tadalafil
Cialis online
سه شنبه 28 خرداد 1398 09:28 ق.ظ

Awesome information. Kudos!
precios cialis peru wow cialis tadalafil 100mg cialis 30 day sample what is cialis cuanto cuesta cialis yaho discount cialis cialis flussig cost of cialis cvs i recommend cialis generico only now cialis for sale in us
http://milgeode.strikingly.com/
دوشنبه 27 خرداد 1398 06:21 ب.ظ

Kudos. Quite a lot of data!

generico cialis mexico rezeptfrei cialis apotheke dose size of cialis cialis e hiv cialis 5mg prix how much does a cialis cost cialis generico online acheter cialis kamagra viagra vs cialis vs levitra cialis vs viagra
Cialis prices
دوشنبه 27 خرداد 1398 03:19 ق.ظ

Many thanks. Plenty of information.

40 mg cialis what if i take miglior cialis generico cialis generico buy cialis online buy name brand cialis on line brand cialis generic cialis daily prices on cialis 10 mg online cialis cialis professional from usa
http://arintraw.strikingly.com/
یکشنبه 26 خرداد 1398 01:47 ب.ظ

This is nicely expressed. !
how to purchase cialis on line opinioni cialis generico trusted tabled cialis softabs cialis for bph precios cialis peru how do cialis pills work bulk cialis cialis et insomni best generic drugs cialis brand cialis nl
http://recoofe.strikingly.com/
شنبه 25 خرداد 1398 11:36 ب.ظ

Thank you. An abundance of tips.

buy name brand cialis on line preis cialis 20mg schweiz sublingual cialis online cialis cuantos mg hay walgreens price for cialis tarif cialis france generic cialis pill online cialis free trial cialis 100 mg 30 tablet il cialis quanto costa
cialis tadalafil online
جمعه 24 خرداد 1398 07:43 ب.ظ

Really a good deal of fantastic information!
sublingual cialis online side effects of cialis venta de cialis canada wow cialis tadalafil 100mg cialis generico in farmacia cialis super kamagra cialis 5 mg para diabeticos purchase once a day cialis cialis 5 mg buy prix cialis once a da
http://westbadni.strikingly.com/
جمعه 24 خرداد 1398 05:05 ق.ظ

Thanks a lot. An abundance of stuff!

cialis australia org ou trouver cialis sur le net what is cialis cialis generika price cialis best cialis generique tadalafil generic cialis 05 cialis 100mg suppliers cialis generico online
buy cialis soft
پنجشنبه 23 خرداد 1398 02:55 ب.ظ

You expressed that perfectly.
cialis 20mg ou trouver cialis sur le net tadalafil 10 mg canadian discount cialis cialis rezeptfrei sterreich cialis kaufen cialis 20mg preis cf cialis vs viagra cialis alternative american pharmacy cialis
Cialis canada
پنجشنبه 23 خرداد 1398 01:26 ق.ظ

Thanks. Helpful stuff!
cialis 100mg suppliers we choice cialis pfizer india generic cialis 20mg tablets cialis patentablauf in deutschland prezzo di cialis in bulgaria achat cialis en suisse buying cialis in colombia generico cialis mexico the best choice cialis woman comprar cialis 10 espa241a
cialisvie.com
سه شنبه 21 خرداد 1398 05:29 ق.ظ

Kudos, An abundance of content.

cialis free trial venta de cialis canada cialis online cialis sicuro in linea dosagem ideal cialis cialis en mexico precio cialis super acti free cialis canadian cialis cialis price thailand
cialisvie.com
دوشنبه 20 خرداد 1398 12:12 ق.ظ

With thanks! Loads of advice.

cialis coupons wow look it cialis mexico cialis 200 dollar savings card tarif cialis france generic cialis in vietnam are there generic cialis we choice free trial of cialis cuanto cuesta cialis yaho cialis coupon buy cialis
http://a2ethics.org/
شنبه 31 فروردین 1398 05:57 ب.ظ
ブランドコピー、ブランドスーパーコピー ルイ?ヴィトン 財布、時計、マフラー,ブランドコピー財布靴下,2018年新作大量入荷
http://sibcbt.ru/slaid
شنبه 31 فروردین 1398 05:56 ب.ظ
ゴヤールバック,財布スーパーコピー 代引き激安市場!
https://www.protekgroup.com/frukty_ovoshi_griby/
جمعه 30 فروردین 1398 10:58 ق.ظ
弊社はサイトで一番大きいブランドコピー品通販ショップです。高い品質、ジャスト プライス!世界の有名ブランドバッグコピー
Cialis canada
جمعه 16 آذر 1397 04:25 ب.ظ

Terrific stuff. Thanks a lot.
if a woman takes a mans cialis buying cialis overnight viagra cialis levitra cialis generico en mexico cialis generico lilly cialis canada cialis online cialis baratos compran uk cialis uk next day prix de cialis
buy cialis online best price
پنجشنبه 15 آذر 1397 09:22 ب.ظ

Excellent facts. Thank you.
buy online cialis 5mg price cialis best achat cialis en europe walgreens price for cialis recommended site cialis kanada cialis canada on line where do you buy cialis cialis soft tabs for sale cialis dosage amounts cialis tadalafil online
buy cialis pills
پنجشنبه 15 آذر 1397 01:50 ق.ظ

With thanks! Helpful stuff!
cialis taglich generic cialis with dapoxetine click here to buy cialis we recommend cheapest cialis acheter du cialis a geneve the best site cialis tablets cialis 5 mg para diabeticos when can i take another cialis cialis 20mg prix en pharmacie cialis generico postepay
Buy generic cialis
چهارشنبه 14 آذر 1397 09:43 ق.ظ

Tips well used..
cilas cialis et insomni cialis for sale in europa cialis sale online cialis dosage cialis flussig cialis italia gratis cialis 20 mg best price buy online cialis 5mg cialis tablets for sale
buy cialis us pharmacy
سه شنبه 13 آذر 1397 10:09 ب.ظ

Regards! An abundance of posts!

generico cialis mexico side effects for cialis viagra or cialis cialis generico en mexico cialis tablets australia cialis great britain canadian discount cialis cialis patentablauf in deutschland buy online cialis 5mg we like it cialis soft gel
buy cialis no rx
سه شنبه 13 آذر 1397 11:19 ق.ظ

Amazing advice. With thanks!
cipla cialis online how does cialis work cialis cuantos mg hay cialis pills 40 mg cialis what if i take cialis tadalafil online venta de cialis canada non 5 mg cialis generici generic cialis tadalafil buying brand cialis online
buy generic cialis pills
دوشنبه 12 آذر 1397 11:33 ب.ظ

Nicely put. Regards!
generic cialis soft gels weblink price cialis tarif cialis france buy cialis online cialis tablets australia cost of cialis cvs where do you buy cialis buy cialis online legal prescription doctor cialis cialis 5 mg funziona
buy generic cialis online
دوشنبه 12 آذر 1397 10:48 ق.ظ

With thanks! I appreciate this.
purchasing cialis on the internet canada discount drugs cialis 5 mg cialis coupon printable how does cialis work price cialis per pill we choice cialis pfizer india generic cialis 20mg uk acheter cialis meilleur pri side effects for cialis pastillas cialis y alcoho
 
لبخندناراحتچشمک
نیشخندبغلسوال
قلبخجالتزبان
ماچتعجبعصبانی
عینکشیطانگریه
خندهقهقههخداحافظ
سبزقهرهورا
دستگلتفکر
نمایش نظرات 1 تا 30