The five fatal flaws in your schedule…

DO YOU SWEAR BY YOUR GANTT CHART?

OR YOUR Line of balance (flowline) diagram?

OR BOTH?

But first 

Let me quickly show you what happens, when you convert your Gantt schedule to a line of balance (flowline) schedule.

From Gantt to Flowline

Take a minute to look at the colored flowlines / activities (Ca, Ms, Pa, El).

When they are copied from the top schedule (Gantt) down to the bottom schedule (location based), you can see what happens, when these lines / activities are divided into locations:

– 2nd floor

– 1st floor

– Ground floor

When the lines / activities are split into locations – they change to the characteristic oblique lines – also known as flowlines.  

These flowlines holds information about both activity, time and location. 

E.g. On May 2nd both carpenter and mason have activities on the 1st floor.  

Buckle up, lets’s get started, and find the five fatal flaws.

Flaw no. 1

Colliding activities

Colliding activities is the first flaw on the list.

In the flowline view, colliding works will appear where two flowlines intersect.  

The result of intersecting lines is that there are more than one set of contractors / disciplines working at the same location at the same time.

Depending on the activities, this may or may not be a problem. 

Maybe the carpentor can install cabinets in the kitchen, at the same time as the mason puts up tiles in the bathroom. 

But if the carpenter is behind schedule, and the walls that the mason needs to put up tiles on in the bathroom, are not build yet, this qualifies as a problem. More often than not, colliding activities are causing waiting / wasted time on site.

When contractors waste time waiting for each other, they earn less money, and it becomes difficult for them to keep a good tone. A “First come, first served” work environment can occur between the contractors on the site and becomes the basis for daily irritation.

Flaw no. 2

Several locations at the construction site is empty… 

…at the same time as colliding and crowded locations elsewhere…

Areas on site are unused.

In the line of balance (locationbased) chart, empty / unused locations will appear as large gaps between the oblique lines. When there is a gap – there are no planned activities on that location.

When locations are not included in the scheduling process, but only time and activities are, the consequence is both Flaw no. 1 and Flaw no. 2.

It will be more or less random which locations are crowded and which ones are empty.

The contractors work on locations – that just happens to be empty that day. This random use of locations, will cause interrupted and unsteady flow and waiting time in the series of activities.

This will have a huge impact on the contractors flat fee – and a on a good and healthy tone on site.  

Flaw no. 3

Time wasted when waiting – ‘start and stop’

Wasted time while waiting is a factor of great importance for the contractors’ workflow and earnings.

In flowlines, “start and stop” can be read as a broken line. As in the illustration above. The painters (yellow) have to man up – or the electricians (red) have to man down – to get a good flow between the two disciplines.

Random activities performed at random locations result in random waiting times. Especially in cases where critical dependencies between the diciplines occur.

Example. The mason cannot put up tiles until the carpenter has completed the wall in the bathroom. There is a critical dependence between carpenters and masons.

If, in this case, there are fewer carpenter’s teams than masonry teams on site, the carpenters’ teams will work “slowly” in the workflow, compared to the masons’ teams who will work “fast”.

This will cause waiting time for the masons. They can not access the location – until the carpenters are finished.

To resolve this issue, the carpenter’s team has to man up – or the mason’s team has to man down – to ensure a good workflow between the two disciplines.

Flaw no. 4

Uneven staffing and flow 

A continuous number of teams from each dicipline, starting at “number 1” and finish at “number 100”, working in a continuous flow with no interruptions and waiting time, is preferable.

A random use of resources / teams on site, are important factors for a lack of consistency on site. 

Example. The carpenters experienced, due to lack of planning, massive waiting time one day when they were 6 teams on site. They decided to send half the teams to another construction site nearby.

If resource / staff planning is not an integrated part of the planning process, the consequence will be a construction site with inconsistency and disruption. Random teams on site, trying to get some work done, only to be shipped of to a different construction site the next day, are not contributing to a healthy environment and workflow on either sites. 

Flaw no. 5

Unable to overview consequences of delays

Once the schedule is made and the construction phase is ongoing, there will always be unforeseen factors that will affect the planned schedule. With Gantt, the consequenses of unforeseen factors and/or delays in a specific location by a specific team, is impossible to visualize and anticipate.

With line of balance (flowlines), on the other hand, you can make forecasts / visualize consequenses of changes and delays. You can illustrate exactly the consequences for a specific dicipline, a specific team, a specific location, for resources concerning a specific team, for dependencies between teams, and finally for the deadline. All these consequences will be visible – in time to make corrections. 

You will also be able to reject “wishful thinking” at weekly meetings in the construction shed. Maybe you have experienced an example similar to this before:

The carpenter is delayed 14 days but reports back: “Hey, don´t worry, we will make it before deadline anyway”.

You will be able to visualize to the carpenter exactly what the consequence of his delay is. You will be able to do so in details. The subsequent painter will not be able to meet his deadline on that specific location – on that specific time – due to this specific delay. The overall deadline will also not be met.

You will also be able to visualize to him, why his wishful thinking is just that and not realistic. The speed he worked with so far, with the amount of men in his team, is visualized as a thin green dotted line in the illustration above. Without manning up, the dotted line will follow its new path. The deadline will be delayed.

If he, on the other hand, does man up in time, the deadline will be met (illustration below).

Do you want to learn more?

Reach out to get a free personal introduction to the method, and a free trial for Tactplan.

Contact Kristina Ekkersgaard, she will help you get started: ke@exigo.dk / +45 53555905