SSK developments

For some, SSK is a well-known concept, while others may be less familiar with it. This 'Standaard Systematiek voor Kostenramingen' (Standard System for Cost Estimating) is a cost estimating methodology for civil engineering and infrastructure projects and was first published in this form in 1999. A few years later, CROW released the second edition of this publication, number 137. At present, the applicable cost estimating methodology for civil engineering cost experts is available from CROW in its third edition under the name 'SSK-2010'.

As SSK needs to evolve with changing developments (including its connection with asset management), CROW has initiated an update. This is scheduled to take place in 2017, conditions and funding permitting. DACE's SIG GWW is involved by CROW in this process and serves as a sounding board.

PIANOo – Public Procurement Expertise Centre

According to SIG GWW, three areas require attention in the updated publication: Life Cycle Costing (LCC), probabilistic cost estimating and internationalisation. The first two topics are already on the agenda. LCC is particularly relevant because of its connection with asset management, while probabilistic cost estimating requires further refinement of the existing theory.

Internationalisation, however, presents a challenge for CROW. CROW considers its role to be focused almost exclusively on the Dutch market and generally does not have the resources to disseminate knowledge internationally, unless there is an explicit demand and, of course, sufficient funding. This is an area in which the SIG may be able to play a role.

Naturally, the SSK spreadsheet will also be reviewed as part of the update. For the time being, however, no further developments are planned. Establishing a set of requirements for 'certified' SSK software is not currently under consideration.

Partly as a result of the new Public Procurement Act, greater emphasis may be placed on Life Cycle Costs in tenders based on the Most Economically Advantageous Tender (MEAT) criterion. A new statutory award criterion may be: 'lowest costs calculated on the basis of cost-effectiveness, such as Life Cycle Costs (LCC)'.

Although the current SSK already makes it possible to calculate Life Cycle Costs, this legislation makes the method used to calculate these costs even more important in order to ensure a fair comparison of tenders based on MEAT. This therefore needs to be standardised.

A working group initiated by the provincial construction expert committee is already working on this issue. SIG GWW is involved with the Public Procurement Expertise Centre (PIANOo) to further develop this approach. This could include, for example, defining terminology or refining the guidelines or calculation model.

The second topic concerns probabilistic cost estimating. The SSK publication describes how this tool can be used to identify the greatest uncertainties within a project. What are the main uncertainties regarding prices or quantities, and which risks have the greatest impact?

SSK-2010 leaves users free to choose how the probabilistic cost calculation is performed. This can be done using an Excel add-in such as Crystal Ball or @RISK, or through the Risicoraming software.

SIG GWW, together with SIG PRA, is working on open-source code that defines the dependencies that should be included in such calculations.

The aim is to ensure that different users obtain the same results from the same input, regardless of the software used.

These considerations are already being taken into account in the SSK update, and the forthcoming CROW SSK working group will address them. This working group will also need to incorporate and harmonise the findings of the LCC working group within SSK.

Finally, many consultancy firms using SSK need a similar methodology for projects abroad, as an (international) standard is often lacking in those markets. Ideas include translating the cost estimating model or the terminology framework into English, or preferably the entire methodology.

However, this is not included in the project that CROW will carry out, as no funding is available for this purpose.

If you have any ideas or comments about SSK after reading about these developments, this is your opportunity to share them! We will discuss them within SIG GWW, and they may be considered for inclusion in a future edition.

Please send your suggestions to info@dace.nl or to the relevant CROW Project Manager, paul.jansen@crow.nl